Update contrib/python/ipython/py3 to 8.3.0

ref:e84342d4d30476f9148137f37fd0c6405fd36f55

9 files changed, 928 insertions, 536 deletions

diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/dtexample.py b/contrib/python/ipython/py3/IPython/testing/plugin/dtexample.py
index d73cd246fd..68f7016e34 100644
--- a/contrib/python/ipython/py3/IPython/testing/plugin/dtexample.py
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/dtexample.py
@@ -4,6 +4,9 @@ This file just contains doctests both using plain python and IPython prompts.
 All tests should be loaded by nose.
 """
 
+import os
+
+
 def pyfunc():
     """Some pure python tests...
 
@@ -35,20 +38,8 @@ def ipfunc():
        ....:     print(i, end=' ')
        ....:     print(i+1, end=' ')
        ....:
-    0 1 1 2 2 3 
-
-
-    Examples that access the operating system work:
-
-    In [1]: !echo hello
-    hello
+    0 1 1 2 2 3
 
-    In [2]: !echo hello > /tmp/foo_iptest
-
-    In [3]: !cat /tmp/foo_iptest
-    hello
-
-    In [4]: rm -f /tmp/foo_iptest
 
     It's OK to use '_' for the last result, but do NOT try to use IPython's
     numbered history of _NN outputs, since those won't exist under the
@@ -59,7 +50,7 @@ def ipfunc():
 
     In [8]: print(repr(_))
     'hi'
-    
+
     In [7]: 3+4
     Out[7]: 7
 
@@ -69,7 +60,26 @@ def ipfunc():
     In [9]: ipfunc()
     Out[9]: 'ipfunc'
     """
-    return 'ipfunc'
+    return "ipfunc"
+
+
+def ipos():
+    """Examples that access the operating system work:
+
+    In [1]: !echo hello
+    hello
+
+    In [2]: !echo hello > /tmp/foo_iptest
+
+    In [3]: !cat /tmp/foo_iptest
+    hello
+
+    In [4]: rm -f /tmp/foo_iptest
+    """
+    pass
+
+
+ipos.__skip_doctest__ = os.name == "nt"
 
 
 def ranfunc():
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/ipdoctest.py b/contrib/python/ipython/py3/IPython/testing/plugin/ipdoctest.py
index 3b8667e72f..52cd8fd3b8 100644
--- a/contrib/python/ipython/py3/IPython/testing/plugin/ipdoctest.py
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/ipdoctest.py
@@ -19,33 +19,13 @@ Limitations:
 # Module imports
 
 # From the standard library
-import builtins as builtin_mod
 import doctest
-import inspect
 import logging
 import os
 import re
-import sys
-from importlib import import_module
-from io import StringIO
 
 from testpath import modified_env
 
-from inspect import getmodule
-
-# We are overriding the default doctest runner, so we need to import a few
-# things from doctest directly
-from doctest import (REPORTING_FLAGS, REPORT_ONLY_FIRST_FAILURE,
-                     _unittest_reportflags, DocTestRunner,
-                     _extract_future_flags, pdb, _OutputRedirectingPdb,
-                     _exception_traceback,
-                     linecache)
-
-# Third-party modules
-
-from nose.plugins import doctests, Plugin
-from nose.util import anyp, tolist
-
 #-----------------------------------------------------------------------------
 # Module globals and other constants
 #-----------------------------------------------------------------------------
@@ -57,114 +37,16 @@ log = logging.getLogger(__name__)
 # Classes and functions
 #-----------------------------------------------------------------------------
 
-def is_extension_module(filename):
-    """Return whether the given filename is an extension module.
-
-    This simply checks that the extension is either .so or .pyd.
-    """
-    return os.path.splitext(filename)[1].lower() in ('.so','.pyd')
-
-
-class DocTestSkip(object):
-    """Object wrapper for doctests to be skipped."""
-
-    ds_skip = """Doctest to skip.
-    >>> 1 #doctest: +SKIP
-    """
-
-    def __init__(self,obj):
-        self.obj = obj
 
-    def __getattribute__(self,key):
-        if key == '__doc__':
-            return DocTestSkip.ds_skip
-        else:
-            return getattr(object.__getattribute__(self,'obj'),key)
-
-# Modified version of the one in the stdlib, that fixes a python bug (doctests
-# not found in extension modules, http://bugs.python.org/issue3158)
 class DocTestFinder(doctest.DocTestFinder):
+    def _get_test(self, obj, name, module, globs, source_lines):
+        test = super()._get_test(obj, name, module, globs, source_lines)
 
-    def _from_module(self, module, object):
-        """
-        Return true if the given object is defined in the given
-        module.
-        """
-        if module is None:
-            return True
-        elif inspect.isfunction(object):
-            return module.__dict__ is object.__globals__
-        elif inspect.isbuiltin(object):
-            return module.__name__ == object.__module__
-        elif inspect.isclass(object):
-            return module.__name__ == object.__module__
-        elif inspect.ismethod(object):
-            # This one may be a bug in cython that fails to correctly set the
-            # __module__ attribute of methods, but since the same error is easy
-            # to make by extension code writers, having this safety in place
-            # isn't such a bad idea
-            return module.__name__ == object.__self__.__class__.__module__
-        elif inspect.getmodule(object) is not None:
-            return module is inspect.getmodule(object)
-        elif hasattr(object, '__module__'):
-            return module.__name__ == object.__module__
-        elif isinstance(object, property):
-            return True # [XX] no way not be sure.
-        elif inspect.ismethoddescriptor(object):
-            # Unbound PyQt signals reach this point in Python 3.4b3, and we want
-            # to avoid throwing an error. See also http://bugs.python.org/issue3158
-            return False
-        else:
-            raise ValueError("object must be a class or function, got %r" % object)
+        if bool(getattr(obj, "__skip_doctest__", False)) and test is not None:
+            for example in test.examples:
+                example.options[doctest.SKIP] = True
 
-    def _find(self, tests, obj, name, module, source_lines, globs, seen):
-        """
-        Find tests for the given object and any contained objects, and
-        add them to `tests`.
-        """
-        print('_find for:', obj, name, module)  # dbg
-        if hasattr(obj,"skip_doctest"):
-            #print 'SKIPPING DOCTEST FOR:',obj  # dbg
-            obj = DocTestSkip(obj)
-        
-        doctest.DocTestFinder._find(self,tests, obj, name, module,
-                                    source_lines, globs, seen)
-
-        # Below we re-run pieces of the above method with manual modifications,
-        # because the original code is buggy and fails to correctly identify
-        # doctests in extension modules.
-
-        # Local shorthands
-        from inspect import isroutine, isclass
-
-        # Look for tests in a module's contained objects.
-        if inspect.ismodule(obj) and self._recurse:
-            for valname, val in obj.__dict__.items():
-                valname1 = '%s.%s' % (name, valname)
-                if ( (isroutine(val) or isclass(val))
-                     and self._from_module(module, val) ):
-
-                    self._find(tests, val, valname1, module, source_lines,
-                               globs, seen)
-
-        # Look for tests in a class's contained objects.
-        if inspect.isclass(obj) and self._recurse:
-            #print 'RECURSE into class:',obj  # dbg
-            for valname, val in obj.__dict__.items():
-                # Special handling for staticmethod/classmethod.
-                if isinstance(val, staticmethod):
-                    val = getattr(obj, valname)
-                if isinstance(val, classmethod):
-                    val = getattr(obj, valname).__func__
-
-                # Recurse to methods, properties, and nested classes.
-                if ((inspect.isfunction(val) or inspect.isclass(val) or
-                     inspect.ismethod(val) or
-                      isinstance(val, property)) and
-                      self._from_module(module, val)):
-                    valname = '%s.%s' % (name, valname)
-                    self._find(tests, val, valname, module, source_lines,
-                               globs, seen)
+        return test
 
 
 class IPDoctestOutputChecker(doctest.OutputChecker):
@@ -193,146 +75,11 @@ class IPDoctestOutputChecker(doctest.OutputChecker):
         return ret
 
 
-class DocTestCase(doctests.DocTestCase):
-    """Proxy for DocTestCase: provides an address() method that
-    returns the correct address for the doctest case. Otherwise
-    acts as a proxy to the test case. To provide hints for address(),
-    an obj may also be passed -- this will be used as the test object
-    for purposes of determining the test address, if it is provided.
-    """
-
-    # Note: this method was taken from numpy's nosetester module.
-
-    # Subclass nose.plugins.doctests.DocTestCase to work around a bug in
-    # its constructor that blocks non-default arguments from being passed
-    # down into doctest.DocTestCase
-
-    def __init__(self, test, optionflags=0, setUp=None, tearDown=None,
-                 checker=None, obj=None, result_var='_'):
-        self._result_var = result_var
-        doctests.DocTestCase.__init__(self, test,
-                                      optionflags=optionflags,
-                                      setUp=setUp, tearDown=tearDown,
-                                      checker=checker)
-        # Now we must actually copy the original constructor from the stdlib
-        # doctest class, because we can't call it directly and a bug in nose
-        # means it never gets passed the right arguments.
-
-        self._dt_optionflags = optionflags
-        self._dt_checker = checker
-        self._dt_test = test
-        self._dt_test_globs_ori = test.globs
-        self._dt_setUp = setUp
-        self._dt_tearDown = tearDown
-
-        # XXX - store this runner once in the object!
-        runner = IPDocTestRunner(optionflags=optionflags,
-                                 checker=checker, verbose=False)
-        self._dt_runner = runner
-
-
-        # Each doctest should remember the directory it was loaded from, so
-        # things like %run work without too many contortions
-        self._ori_dir = os.path.dirname(test.filename)
-
-    # Modified runTest from the default stdlib
-    def runTest(self):
-        test = self._dt_test
-        runner = self._dt_runner
-
-        old = sys.stdout
-        new = StringIO()
-        optionflags = self._dt_optionflags
-
-        if not (optionflags & REPORTING_FLAGS):
-            # The option flags don't include any reporting flags,
-            # so add the default reporting flags
-            optionflags |= _unittest_reportflags
-
-        try:
-            # Save our current directory and switch out to the one where the
-            # test was originally created, in case another doctest did a
-            # directory change.  We'll restore this in the finally clause.
-            curdir = os.getcwd()
-            #print 'runTest in dir:', self._ori_dir  # dbg
-            os.chdir(self._ori_dir)
-
-            runner.DIVIDER = "-"*70
-            failures, tries = runner.run(test,out=new.write,
-                                         clear_globs=False)
-        finally:
-            sys.stdout = old
-            os.chdir(curdir)
-
-        if failures:
-            raise self.failureException(self.format_failure(new.getvalue()))
-
-    def setUp(self):
-        """Modified test setup that syncs with ipython namespace"""
-        #print "setUp test", self._dt_test.examples # dbg
-        if isinstance(self._dt_test.examples[0], IPExample):
-            # for IPython examples *only*, we swap the globals with the ipython
-            # namespace, after updating it with the globals (which doctest
-            # fills with the necessary info from the module being tested).
-            self.user_ns_orig = {}
-            self.user_ns_orig.update(_ip.user_ns)
-            _ip.user_ns.update(self._dt_test.globs)
-            # We must remove the _ key in the namespace, so that Python's
-            # doctest code sets it naturally
-            _ip.user_ns.pop('_', None)
-            _ip.user_ns['__builtins__'] = builtin_mod
-            self._dt_test.globs = _ip.user_ns
-
-        super(DocTestCase, self).setUp()
-
-    def tearDown(self):
-
-        # Undo the test.globs reassignment we made, so that the parent class
-        # teardown doesn't destroy the ipython namespace
-        if isinstance(self._dt_test.examples[0], IPExample):
-            self._dt_test.globs = self._dt_test_globs_ori
-            _ip.user_ns.clear()
-            _ip.user_ns.update(self.user_ns_orig)
-
-        # XXX - fperez: I am not sure if this is truly a bug in nose 0.11, but
-        # it does look like one to me: its tearDown method tries to run
-        #
-        # delattr(builtin_mod, self._result_var)
-        #
-        # without checking that the attribute really is there; it implicitly
-        # assumes it should have been set via displayhook.  But if the
-        # displayhook was never called, this doesn't necessarily happen.  I
-        # haven't been able to find a little self-contained example outside of
-        # ipython that would show the problem so I can report it to the nose
-        # team, but it does happen a lot in our code.
-        #
-        # So here, we just protect as narrowly as possible by trapping an
-        # attribute error whose message would be the name of self._result_var,
-        # and letting any other error propagate.
-        try:
-            super(DocTestCase, self).tearDown()
-        except AttributeError as exc:
-            if exc.args[0] != self._result_var:
-                raise
-
-
 # A simple subclassing of the original with a different class name, so we can
 # distinguish and treat differently IPython examples from pure python ones.
 class IPExample(doctest.Example): pass
 
 
-class IPExternalExample(doctest.Example):
-    """Doctest examples to be run in an external process."""
-
-    def __init__(self, source, want, exc_msg=None, lineno=0, indent=0,
-                 options=None):
-        # Parent constructor
-        doctest.Example.__init__(self,source,want,exc_msg,lineno,indent,options)
-
-        # An EXTRA newline is needed to prevent pexpect hangs
-        self.source += '\n'
-
-
 class IPDocTestParser(doctest.DocTestParser):
     """
     A class used to parse strings containing doctest examples.
@@ -378,9 +125,6 @@ class IPDocTestParser(doctest.DocTestParser):
     # we don't need to modify any other code.
     _RANDOM_TEST = re.compile(r'#\s*all-random\s+')
 
-    # Mark tests to be executed in an external process - currently unsupported.
-    _EXTERNAL_IP = re.compile(r'#\s*ipdoctest:\s*EXTERNAL')
-
     def ip2py(self,source):
         """Convert input IPython source into valid Python."""
         block = _ip.input_transformer_manager.transform_cell(source)
@@ -423,27 +167,12 @@ class IPDocTestParser(doctest.DocTestParser):
         terms = list(self._EXAMPLE_RE_PY.finditer(string))
         if terms:
             # Normal Python example
-            #print '-'*70  # dbg
-            #print 'PyExample, Source:\n',string  # dbg
-            #print '-'*70  # dbg
             Example = doctest.Example
         else:
-            # It's an ipython example.  Note that IPExamples are run
-            # in-process, so their syntax must be turned into valid python.
-            # IPExternalExamples are run out-of-process (via pexpect) so they
-            # don't need any filtering (a real ipython will be executing them).
+            # It's an ipython example.
             terms = list(self._EXAMPLE_RE_IP.finditer(string))
-            if self._EXTERNAL_IP.search(string):
-                #print '-'*70  # dbg
-                #print 'IPExternalExample, Source:\n',string  # dbg
-                #print '-'*70  # dbg
-                Example = IPExternalExample
-            else:
-                #print '-'*70  # dbg
-                #print 'IPExample, Source:\n',string  # dbg
-                #print '-'*70  # dbg
-                Example = IPExample
-                ip2py = True
+            Example = IPExample
+            ip2py = True
 
         for m in terms:
             # Add the pre-example text to `output`.
@@ -458,10 +187,6 @@ class IPDocTestParser(doctest.DocTestParser):
             # cases, it's only non-empty for 'all-random' tests):
             want += random_marker
 
-            if Example is IPExternalExample:
-                options[doctest.NORMALIZE_WHITESPACE] = True
-                want += '\n'
-
             # Create an Example, and add it to the list.
             if not self._IS_BLANK_OR_COMMENT(source):
                 output.append(Example(source, want, exc_msg,
@@ -569,193 +294,7 @@ class IPDocTestRunner(doctest.DocTestRunner,object):
     """
 
     def run(self, test, compileflags=None, out=None, clear_globs=True):
-
-        # Hack: ipython needs access to the execution context of the example,
-        # so that it can propagate user variables loaded by %run into
-        # test.globs.  We put them here into our modified %run as a function
-        # attribute.  Our new %run will then only make the namespace update
-        # when called (rather than unconditionally updating test.globs here
-        # for all examples, most of which won't be calling %run anyway).
-        #_ip._ipdoctest_test_globs = test.globs
-        #_ip._ipdoctest_test_filename = test.filename
-
-        test.globs.update(_ip.user_ns)
-
         # Override terminal size to standardise traceback format
         with modified_env({'COLUMNS': '80', 'LINES': '24'}):
             return super(IPDocTestRunner,self).run(test,
                                                    compileflags,out,clear_globs)
-
-
-class DocFileCase(doctest.DocFileCase):
-    """Overrides to provide filename
-    """
-    def address(self):
-        return (self._dt_test.filename, None, None)
-
-
-class ExtensionDoctest(doctests.Doctest):
-    """Nose Plugin that supports doctests in extension modules.
-    """
-    name = 'extdoctest'   # call nosetests with --with-extdoctest
-    enabled = True
-
-    def options(self, parser, env=os.environ):
-        Plugin.options(self, parser, env)
-        parser.add_option('--doctest-tests', action='store_true',
-                          dest='doctest_tests',
-                          default=env.get('NOSE_DOCTEST_TESTS',True),
-                          help="Also look for doctests in test modules. "
-                          "Note that classes, methods and functions should "
-                          "have either doctests or non-doctest tests, "
-                          "not both. [NOSE_DOCTEST_TESTS]")
-        parser.add_option('--doctest-extension', action="append",
-                          dest="doctestExtension",
-                          help="Also look for doctests in files with "
-                          "this extension [NOSE_DOCTEST_EXTENSION]")
-        # Set the default as a list, if given in env; otherwise
-        # an additional value set on the command line will cause
-        # an error.
-        env_setting = env.get('NOSE_DOCTEST_EXTENSION')
-        if env_setting is not None:
-            parser.set_defaults(doctestExtension=tolist(env_setting))
-
-
-    def configure(self, options, config):
-        Plugin.configure(self, options, config)
-        # Pull standard doctest plugin out of config; we will do doctesting
-        config.plugins.plugins = [p for p in config.plugins.plugins
-                                  if p.name != 'doctest']
-        self.doctest_tests = options.doctest_tests
-        self.extension = tolist(options.doctestExtension)
-
-        self.parser = doctest.DocTestParser()
-        self.finder = DocTestFinder()
-        self.checker = IPDoctestOutputChecker()
-        self.globs = None
-        self.extraglobs = None
-
-
-    def loadTestsFromExtensionModule(self,filename):
-        bpath,mod = os.path.split(filename)
-        modname = os.path.splitext(mod)[0]
-        try:
-            sys.path.append(bpath)
-            module = import_module(modname)
-            tests = list(self.loadTestsFromModule(module))
-        finally:
-            sys.path.pop()
-        return tests
-
-    # NOTE: the method below is almost a copy of the original one in nose, with
-    # a  few modifications to control output checking.
-
-    def loadTestsFromModule(self, module):
-        #print '*** ipdoctest - lTM',module  # dbg
-
-        if not self.matches(module.__name__):
-            log.debug("Doctest doesn't want module %s", module)
-            return
-
-        tests = self.finder.find(module,globs=self.globs,
-                                 extraglobs=self.extraglobs)
-        if not tests:
-            return
-
-        # always use whitespace and ellipsis options
-        optionflags = doctest.NORMALIZE_WHITESPACE | doctest.ELLIPSIS
-
-        tests.sort()
-        module_file = module.__file__
-        if module_file[-4:] in ('.pyc', '.pyo'):
-            module_file = module_file[:-1]
-        for test in tests:
-            if not test.examples:
-                continue
-            if not test.filename:
-                test.filename = module_file
-
-            yield DocTestCase(test,
-                              optionflags=optionflags,
-                              checker=self.checker)
-
-
-    def loadTestsFromFile(self, filename):
-        #print "ipdoctest - from file", filename # dbg
-        if is_extension_module(filename):
-            for t in self.loadTestsFromExtensionModule(filename):
-                yield t
-        else:
-            if self.extension and anyp(filename.endswith, self.extension):
-                name = os.path.basename(filename)
-                with open(filename) as dh:
-                    doc = dh.read()
-                test = self.parser.get_doctest(
-                    doc, globs={'__file__': filename}, name=name,
-                    filename=filename, lineno=0)
-                if test.examples:
-                    #print 'FileCase:',test.examples  # dbg
-                    yield DocFileCase(test)
-                else:
-                    yield False # no tests to load
-
-
-class IPythonDoctest(ExtensionDoctest):
-    """Nose Plugin that supports doctests in extension modules.
-    """
-    name = 'ipdoctest'   # call nosetests with --with-ipdoctest
-    enabled = True
-
-    def makeTest(self, obj, parent):
-        """Look for doctests in the given object, which will be a
-        function, method or class.
-        """
-        #print 'Plugin analyzing:', obj, parent  # dbg
-        # always use whitespace and ellipsis options
-        optionflags = doctest.NORMALIZE_WHITESPACE | doctest.ELLIPSIS
-
-        doctests = self.finder.find(obj, module=getmodule(parent))
-        if doctests:
-            for test in doctests:
-                if len(test.examples) == 0:
-                    continue
-
-                yield DocTestCase(test, obj=obj,
-                                  optionflags=optionflags,
-                                  checker=self.checker)
-
-    def options(self, parser, env=os.environ):
-        #print "Options for nose plugin:", self.name # dbg
-        Plugin.options(self, parser, env)
-        parser.add_option('--ipdoctest-tests', action='store_true',
-                          dest='ipdoctest_tests',
-                          default=env.get('NOSE_IPDOCTEST_TESTS',True),
-                          help="Also look for doctests in test modules. "
-                          "Note that classes, methods and functions should "
-                          "have either doctests or non-doctest tests, "
-                          "not both. [NOSE_IPDOCTEST_TESTS]")
-        parser.add_option('--ipdoctest-extension', action="append",
-                          dest="ipdoctest_extension",
-                          help="Also look for doctests in files with "
-                          "this extension [NOSE_IPDOCTEST_EXTENSION]")
-        # Set the default as a list, if given in env; otherwise
-        # an additional value set on the command line will cause
-        # an error.
-        env_setting = env.get('NOSE_IPDOCTEST_EXTENSION')
-        if env_setting is not None:
-            parser.set_defaults(ipdoctest_extension=tolist(env_setting))
-
-    def configure(self, options, config):
-        #print "Configuring nose plugin:", self.name # dbg
-        Plugin.configure(self, options, config)
-        # Pull standard doctest plugin out of config; we will do doctesting
-        config.plugins.plugins = [p for p in config.plugins.plugins
-                                  if p.name != 'doctest']
-        self.doctest_tests = options.ipdoctest_tests
-        self.extension = tolist(options.ipdoctest_extension)
-
-        self.parser = IPDocTestParser()
-        self.finder = DocTestFinder(parser=self.parser)
-        self.checker = IPDoctestOutputChecker()
-        self.globs = None
-        self.extraglobs = None
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/iptest.py b/contrib/python/ipython/py3/IPython/testing/plugin/iptest.py
deleted file mode 100644
index e24e22a830..0000000000
--- a/contrib/python/ipython/py3/IPython/testing/plugin/iptest.py
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/usr/bin/env python
-"""Nose-based test runner.
-"""
-
-from nose.core import main
-from nose.plugins.builtin import plugins
-from nose.plugins.doctests import Doctest
-
-from . import ipdoctest
-from .ipdoctest import IPDocTestRunner
-
-if __name__ == '__main__':
-    print('WARNING: this code is incomplete!')
-    print()
-
-    pp = [x() for x in plugins]  # activate all builtin plugins first
-    main(testRunner=IPDocTestRunner(),
-         plugins=pp+[ipdoctest.IPythonDoctest(),Doctest()])
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/pytest_ipdoctest.py b/contrib/python/ipython/py3/IPython/testing/plugin/pytest_ipdoctest.py
new file mode 100644
index 0000000000..809713d7c8
--- /dev/null
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/pytest_ipdoctest.py
@@ -0,0 +1,860 @@
+# Based on Pytest doctest.py
+# Original license:
+# The MIT License (MIT)
+#
+# Copyright (c) 2004-2021 Holger Krekel and others
+"""Discover and run ipdoctests in modules and test files."""
+import builtins
+import bdb
+import inspect
+import os
+import platform
+import sys
+import traceback
+import types
+import warnings
+from contextlib import contextmanager
+from pathlib import Path
+from typing import Any
+from typing import Callable
+from typing import Dict
+from typing import Generator
+from typing import Iterable
+from typing import List
+from typing import Optional
+from typing import Pattern
+from typing import Sequence
+from typing import Tuple
+from typing import Type
+from typing import TYPE_CHECKING
+from typing import Union
+
+import pytest
+from _pytest import outcomes
+from _pytest._code.code import ExceptionInfo
+from _pytest._code.code import ReprFileLocation
+from _pytest._code.code import TerminalRepr
+from _pytest._io import TerminalWriter
+from _pytest.compat import safe_getattr
+from _pytest.config import Config
+from _pytest.config.argparsing import Parser
+from _pytest.fixtures import FixtureRequest
+from _pytest.nodes import Collector
+from _pytest.outcomes import OutcomeException
+from _pytest.pathlib import fnmatch_ex
+from _pytest.pathlib import import_path
+from _pytest.python_api import approx
+from _pytest.warning_types import PytestWarning
+
+if TYPE_CHECKING:
+    import doctest
+
+DOCTEST_REPORT_CHOICE_NONE = "none"
+DOCTEST_REPORT_CHOICE_CDIFF = "cdiff"
+DOCTEST_REPORT_CHOICE_NDIFF = "ndiff"
+DOCTEST_REPORT_CHOICE_UDIFF = "udiff"
+DOCTEST_REPORT_CHOICE_ONLY_FIRST_FAILURE = "only_first_failure"
+
+DOCTEST_REPORT_CHOICES = (
+    DOCTEST_REPORT_CHOICE_NONE,
+    DOCTEST_REPORT_CHOICE_CDIFF,
+    DOCTEST_REPORT_CHOICE_NDIFF,
+    DOCTEST_REPORT_CHOICE_UDIFF,
+    DOCTEST_REPORT_CHOICE_ONLY_FIRST_FAILURE,
+)
+
+# Lazy definition of runner class
+RUNNER_CLASS = None
+# Lazy definition of output checker class
+CHECKER_CLASS: Optional[Type["IPDoctestOutputChecker"]] = None
+
+
+def pytest_addoption(parser: Parser) -> None:
+    parser.addini(
+        "ipdoctest_optionflags",
+        "option flags for ipdoctests",
+        type="args",
+        default=["ELLIPSIS"],
+    )
+    parser.addini(
+        "ipdoctest_encoding", "encoding used for ipdoctest files", default="utf-8"
+    )
+    group = parser.getgroup("collect")
+    group.addoption(
+        "--ipdoctest-modules",
+        action="store_true",
+        default=False,
+        help="run ipdoctests in all .py modules",
+        dest="ipdoctestmodules",
+    )
+    group.addoption(
+        "--ipdoctest-report",
+        type=str.lower,
+        default="udiff",
+        help="choose another output format for diffs on ipdoctest failure",
+        choices=DOCTEST_REPORT_CHOICES,
+        dest="ipdoctestreport",
+    )
+    group.addoption(
+        "--ipdoctest-glob",
+        action="append",
+        default=[],
+        metavar="pat",
+        help="ipdoctests file matching pattern, default: test*.txt",
+        dest="ipdoctestglob",
+    )
+    group.addoption(
+        "--ipdoctest-ignore-import-errors",
+        action="store_true",
+        default=False,
+        help="ignore ipdoctest ImportErrors",
+        dest="ipdoctest_ignore_import_errors",
+    )
+    group.addoption(
+        "--ipdoctest-continue-on-failure",
+        action="store_true",
+        default=False,
+        help="for a given ipdoctest, continue to run after the first failure",
+        dest="ipdoctest_continue_on_failure",
+    )
+
+
+def pytest_unconfigure() -> None:
+    global RUNNER_CLASS
+
+    RUNNER_CLASS = None
+
+
+def pytest_collect_file(
+    file_path: Path,
+    parent: Collector,
+) -> Optional[Union["IPDoctestModule", "IPDoctestTextfile"]]:
+    config = parent.config
+    if file_path.suffix == ".py":
+        if config.option.ipdoctestmodules and not any(
+            (_is_setup_py(file_path), _is_main_py(file_path))
+        ):
+            mod: IPDoctestModule = IPDoctestModule.from_parent(parent, path=file_path)
+            return mod
+    elif _is_ipdoctest(config, file_path, parent):
+        txt: IPDoctestTextfile = IPDoctestTextfile.from_parent(parent, path=file_path)
+        return txt
+    return None
+
+
+if int(pytest.__version__.split(".")[0]) < 7:
+    _collect_file = pytest_collect_file
+
+    def pytest_collect_file(
+        path,
+        parent: Collector,
+    ) -> Optional[Union["IPDoctestModule", "IPDoctestTextfile"]]:
+        return _collect_file(Path(path), parent)
+
+    _import_path = import_path
+
+    def import_path(path, root):
+        import py.path
+
+        return _import_path(py.path.local(path))
+
+
+def _is_setup_py(path: Path) -> bool:
+    if path.name != "setup.py":
+        return False
+    contents = path.read_bytes()
+    return b"setuptools" in contents or b"distutils" in contents
+
+
+def _is_ipdoctest(config: Config, path: Path, parent: Collector) -> bool:
+    if path.suffix in (".txt", ".rst") and parent.session.isinitpath(path):
+        return True
+    globs = config.getoption("ipdoctestglob") or ["test*.txt"]
+    return any(fnmatch_ex(glob, path) for glob in globs)
+
+
+def _is_main_py(path: Path) -> bool:
+    return path.name == "__main__.py"
+
+
+class ReprFailDoctest(TerminalRepr):
+    def __init__(
+        self, reprlocation_lines: Sequence[Tuple[ReprFileLocation, Sequence[str]]]
+    ) -> None:
+        self.reprlocation_lines = reprlocation_lines
+
+    def toterminal(self, tw: TerminalWriter) -> None:
+        for reprlocation, lines in self.reprlocation_lines:
+            for line in lines:
+                tw.line(line)
+            reprlocation.toterminal(tw)
+
+
+class MultipleDoctestFailures(Exception):
+    def __init__(self, failures: Sequence["doctest.DocTestFailure"]) -> None:
+        super().__init__()
+        self.failures = failures
+
+
+def _init_runner_class() -> Type["IPDocTestRunner"]:
+    import doctest
+    from .ipdoctest import IPDocTestRunner
+
+    class PytestDoctestRunner(IPDocTestRunner):
+        """Runner to collect failures.
+
+        Note that the out variable in this case is a list instead of a
+        stdout-like object.
+        """
+
+        def __init__(
+            self,
+            checker: Optional["IPDoctestOutputChecker"] = None,
+            verbose: Optional[bool] = None,
+            optionflags: int = 0,
+            continue_on_failure: bool = True,
+        ) -> None:
+            super().__init__(checker=checker, verbose=verbose, optionflags=optionflags)
+            self.continue_on_failure = continue_on_failure
+
+        def report_failure(
+            self,
+            out,
+            test: "doctest.DocTest",
+            example: "doctest.Example",
+            got: str,
+        ) -> None:
+            failure = doctest.DocTestFailure(test, example, got)
+            if self.continue_on_failure:
+                out.append(failure)
+            else:
+                raise failure
+
+        def report_unexpected_exception(
+            self,
+            out,
+            test: "doctest.DocTest",
+            example: "doctest.Example",
+            exc_info: Tuple[Type[BaseException], BaseException, types.TracebackType],
+        ) -> None:
+            if isinstance(exc_info[1], OutcomeException):
+                raise exc_info[1]
+            if isinstance(exc_info[1], bdb.BdbQuit):
+                outcomes.exit("Quitting debugger")
+            failure = doctest.UnexpectedException(test, example, exc_info)
+            if self.continue_on_failure:
+                out.append(failure)
+            else:
+                raise failure
+
+    return PytestDoctestRunner
+
+
+def _get_runner(
+    checker: Optional["IPDoctestOutputChecker"] = None,
+    verbose: Optional[bool] = None,
+    optionflags: int = 0,
+    continue_on_failure: bool = True,
+) -> "IPDocTestRunner":
+    # We need this in order to do a lazy import on doctest
+    global RUNNER_CLASS
+    if RUNNER_CLASS is None:
+        RUNNER_CLASS = _init_runner_class()
+    # Type ignored because the continue_on_failure argument is only defined on
+    # PytestDoctestRunner, which is lazily defined so can't be used as a type.
+    return RUNNER_CLASS(  # type: ignore
+        checker=checker,
+        verbose=verbose,
+        optionflags=optionflags,
+        continue_on_failure=continue_on_failure,
+    )
+
+
+class IPDoctestItem(pytest.Item):
+    def __init__(
+        self,
+        name: str,
+        parent: "Union[IPDoctestTextfile, IPDoctestModule]",
+        runner: Optional["IPDocTestRunner"] = None,
+        dtest: Optional["doctest.DocTest"] = None,
+    ) -> None:
+        super().__init__(name, parent)
+        self.runner = runner
+        self.dtest = dtest
+        self.obj = None
+        self.fixture_request: Optional[FixtureRequest] = None
+
+    @classmethod
+    def from_parent(  # type: ignore
+        cls,
+        parent: "Union[IPDoctestTextfile, IPDoctestModule]",
+        *,
+        name: str,
+        runner: "IPDocTestRunner",
+        dtest: "doctest.DocTest",
+    ):
+        # incompatible signature due to imposed limits on subclass
+        """The public named constructor."""
+        return super().from_parent(name=name, parent=parent, runner=runner, dtest=dtest)
+
+    def setup(self) -> None:
+        if self.dtest is not None:
+            self.fixture_request = _setup_fixtures(self)
+            globs = dict(getfixture=self.fixture_request.getfixturevalue)
+            for name, value in self.fixture_request.getfixturevalue(
+                "ipdoctest_namespace"
+            ).items():
+                globs[name] = value
+            self.dtest.globs.update(globs)
+
+            from .ipdoctest import IPExample
+
+            if isinstance(self.dtest.examples[0], IPExample):
+                # for IPython examples *only*, we swap the globals with the ipython
+                # namespace, after updating it with the globals (which doctest
+                # fills with the necessary info from the module being tested).
+                self._user_ns_orig = {}
+                self._user_ns_orig.update(_ip.user_ns)
+                _ip.user_ns.update(self.dtest.globs)
+                # We must remove the _ key in the namespace, so that Python's
+                # doctest code sets it naturally
+                _ip.user_ns.pop("_", None)
+                _ip.user_ns["__builtins__"] = builtins
+                self.dtest.globs = _ip.user_ns
+
+    def teardown(self) -> None:
+        from .ipdoctest import IPExample
+
+        # Undo the test.globs reassignment we made
+        if isinstance(self.dtest.examples[0], IPExample):
+            self.dtest.globs = {}
+            _ip.user_ns.clear()
+            _ip.user_ns.update(self._user_ns_orig)
+            del self._user_ns_orig
+
+        self.dtest.globs.clear()
+
+    def runtest(self) -> None:
+        assert self.dtest is not None
+        assert self.runner is not None
+        _check_all_skipped(self.dtest)
+        self._disable_output_capturing_for_darwin()
+        failures: List["doctest.DocTestFailure"] = []
+
+        # exec(compile(..., "single", ...), ...) puts result in builtins._
+        had_underscore_value = hasattr(builtins, "_")
+        underscore_original_value = getattr(builtins, "_", None)
+
+        # Save our current directory and switch out to the one where the
+        # test was originally created, in case another doctest did a
+        # directory change.  We'll restore this in the finally clause.
+        curdir = os.getcwd()
+        os.chdir(self.fspath.dirname)
+        try:
+            # Type ignored because we change the type of `out` from what
+            # ipdoctest expects.
+            self.runner.run(self.dtest, out=failures, clear_globs=False)  # type: ignore[arg-type]
+        finally:
+            os.chdir(curdir)
+            if had_underscore_value:
+                setattr(builtins, "_", underscore_original_value)
+            elif hasattr(builtins, "_"):
+                delattr(builtins, "_")
+
+        if failures:
+            raise MultipleDoctestFailures(failures)
+
+    def _disable_output_capturing_for_darwin(self) -> None:
+        """Disable output capturing. Otherwise, stdout is lost to ipdoctest (pytest#985)."""
+        if platform.system() != "Darwin":
+            return
+        capman = self.config.pluginmanager.getplugin("capturemanager")
+        if capman:
+            capman.suspend_global_capture(in_=True)
+            out, err = capman.read_global_capture()
+            sys.stdout.write(out)
+            sys.stderr.write(err)
+
+    # TODO: Type ignored -- breaks Liskov Substitution.
+    def repr_failure(  # type: ignore[override]
+        self,
+        excinfo: ExceptionInfo[BaseException],
+    ) -> Union[str, TerminalRepr]:
+        import doctest
+
+        failures: Optional[
+            Sequence[Union[doctest.DocTestFailure, doctest.UnexpectedException]]
+        ] = None
+        if isinstance(
+            excinfo.value, (doctest.DocTestFailure, doctest.UnexpectedException)
+        ):
+            failures = [excinfo.value]
+        elif isinstance(excinfo.value, MultipleDoctestFailures):
+            failures = excinfo.value.failures
+
+        if failures is None:
+            return super().repr_failure(excinfo)
+
+        reprlocation_lines = []
+        for failure in failures:
+            example = failure.example
+            test = failure.test
+            filename = test.filename
+            if test.lineno is None:
+                lineno = None
+            else:
+                lineno = test.lineno + example.lineno + 1
+            message = type(failure).__name__
+            # TODO: ReprFileLocation doesn't expect a None lineno.
+            reprlocation = ReprFileLocation(filename, lineno, message)  # type: ignore[arg-type]
+            checker = _get_checker()
+            report_choice = _get_report_choice(self.config.getoption("ipdoctestreport"))
+            if lineno is not None:
+                assert failure.test.docstring is not None
+                lines = failure.test.docstring.splitlines(False)
+                # add line numbers to the left of the error message
+                assert test.lineno is not None
+                lines = [
+                    "%03d %s" % (i + test.lineno + 1, x) for (i, x) in enumerate(lines)
+                ]
+                # trim docstring error lines to 10
+                lines = lines[max(example.lineno - 9, 0) : example.lineno + 1]
+            else:
+                lines = [
+                    "EXAMPLE LOCATION UNKNOWN, not showing all tests of that example"
+                ]
+                indent = ">>>"
+                for line in example.source.splitlines():
+                    lines.append(f"??? {indent} {line}")
+                    indent = "..."
+            if isinstance(failure, doctest.DocTestFailure):
+                lines += checker.output_difference(
+                    example, failure.got, report_choice
+                ).split("\n")
+            else:
+                inner_excinfo = ExceptionInfo.from_exc_info(failure.exc_info)
+                lines += ["UNEXPECTED EXCEPTION: %s" % repr(inner_excinfo.value)]
+                lines += [
+                    x.strip("\n") for x in traceback.format_exception(*failure.exc_info)
+                ]
+            reprlocation_lines.append((reprlocation, lines))
+        return ReprFailDoctest(reprlocation_lines)
+
+    def reportinfo(self) -> Tuple[Union["os.PathLike[str]", str], Optional[int], str]:
+        assert self.dtest is not None
+        return self.path, self.dtest.lineno, "[ipdoctest] %s" % self.name
+
+    if int(pytest.__version__.split(".")[0]) < 7:
+
+        @property
+        def path(self) -> Path:
+            return Path(self.fspath)
+
+
+def _get_flag_lookup() -> Dict[str, int]:
+    import doctest
+
+    return dict(
+        DONT_ACCEPT_TRUE_FOR_1=doctest.DONT_ACCEPT_TRUE_FOR_1,
+        DONT_ACCEPT_BLANKLINE=doctest.DONT_ACCEPT_BLANKLINE,
+        NORMALIZE_WHITESPACE=doctest.NORMALIZE_WHITESPACE,
+        ELLIPSIS=doctest.ELLIPSIS,
+        IGNORE_EXCEPTION_DETAIL=doctest.IGNORE_EXCEPTION_DETAIL,
+        COMPARISON_FLAGS=doctest.COMPARISON_FLAGS,
+        ALLOW_UNICODE=_get_allow_unicode_flag(),
+        ALLOW_BYTES=_get_allow_bytes_flag(),
+        NUMBER=_get_number_flag(),
+    )
+
+
+def get_optionflags(parent):
+    optionflags_str = parent.config.getini("ipdoctest_optionflags")
+    flag_lookup_table = _get_flag_lookup()
+    flag_acc = 0
+    for flag in optionflags_str:
+        flag_acc |= flag_lookup_table[flag]
+    return flag_acc
+
+
+def _get_continue_on_failure(config):
+    continue_on_failure = config.getvalue("ipdoctest_continue_on_failure")
+    if continue_on_failure:
+        # We need to turn off this if we use pdb since we should stop at
+        # the first failure.
+        if config.getvalue("usepdb"):
+            continue_on_failure = False
+    return continue_on_failure
+
+
+class IPDoctestTextfile(pytest.Module):
+    obj = None
+
+    def collect(self) -> Iterable[IPDoctestItem]:
+        import doctest
+        from .ipdoctest import IPDocTestParser
+
+        # Inspired by doctest.testfile; ideally we would use it directly,
+        # but it doesn't support passing a custom checker.
+        encoding = self.config.getini("ipdoctest_encoding")
+        text = self.path.read_text(encoding)
+        filename = str(self.path)
+        name = self.path.name
+        globs = {"__name__": "__main__"}
+
+        optionflags = get_optionflags(self)
+
+        runner = _get_runner(
+            verbose=False,
+            optionflags=optionflags,
+            checker=_get_checker(),
+            continue_on_failure=_get_continue_on_failure(self.config),
+        )
+
+        parser = IPDocTestParser()
+        test = parser.get_doctest(text, globs, name, filename, 0)
+        if test.examples:
+            yield IPDoctestItem.from_parent(
+                self, name=test.name, runner=runner, dtest=test
+            )
+
+    if int(pytest.__version__.split(".")[0]) < 7:
+
+        @property
+        def path(self) -> Path:
+            return Path(self.fspath)
+
+        @classmethod
+        def from_parent(
+            cls,
+            parent,
+            *,
+            fspath=None,
+            path: Optional[Path] = None,
+            **kw,
+        ):
+            if path is not None:
+                import py.path
+
+                fspath = py.path.local(path)
+            return super().from_parent(parent=parent, fspath=fspath, **kw)
+
+
+def _check_all_skipped(test: "doctest.DocTest") -> None:
+    """Raise pytest.skip() if all examples in the given DocTest have the SKIP
+    option set."""
+    import doctest
+
+    all_skipped = all(x.options.get(doctest.SKIP, False) for x in test.examples)
+    if all_skipped:
+        pytest.skip("all docstests skipped by +SKIP option")
+
+
+def _is_mocked(obj: object) -> bool:
+    """Return if an object is possibly a mock object by checking the
+    existence of a highly improbable attribute."""
+    return (
+        safe_getattr(obj, "pytest_mock_example_attribute_that_shouldnt_exist", None)
+        is not None
+    )
+
+
+@contextmanager
+def _patch_unwrap_mock_aware() -> Generator[None, None, None]:
+    """Context manager which replaces ``inspect.unwrap`` with a version
+    that's aware of mock objects and doesn't recurse into them."""
+    real_unwrap = inspect.unwrap
+
+    def _mock_aware_unwrap(
+        func: Callable[..., Any], *, stop: Optional[Callable[[Any], Any]] = None
+    ) -> Any:
+        try:
+            if stop is None or stop is _is_mocked:
+                return real_unwrap(func, stop=_is_mocked)
+            _stop = stop
+            return real_unwrap(func, stop=lambda obj: _is_mocked(obj) or _stop(func))
+        except Exception as e:
+            warnings.warn(
+                "Got %r when unwrapping %r.  This is usually caused "
+                "by a violation of Python's object protocol; see e.g. "
+                "https://github.com/pytest-dev/pytest/issues/5080" % (e, func),
+                PytestWarning,
+            )
+            raise
+
+    inspect.unwrap = _mock_aware_unwrap
+    try:
+        yield
+    finally:
+        inspect.unwrap = real_unwrap
+
+
+class IPDoctestModule(pytest.Module):
+    def collect(self) -> Iterable[IPDoctestItem]:
+        import doctest
+        from .ipdoctest import DocTestFinder, IPDocTestParser
+
+        class MockAwareDocTestFinder(DocTestFinder):
+            """A hackish ipdoctest finder that overrides stdlib internals to fix a stdlib bug.
+
+            https://github.com/pytest-dev/pytest/issues/3456
+            https://bugs.python.org/issue25532
+            """
+
+            def _find_lineno(self, obj, source_lines):
+                """Doctest code does not take into account `@property`, this
+                is a hackish way to fix it. https://bugs.python.org/issue17446
+
+                Wrapped Doctests will need to be unwrapped so the correct
+                line number is returned. This will be reported upstream. #8796
+                """
+                if isinstance(obj, property):
+                    obj = getattr(obj, "fget", obj)
+
+                if hasattr(obj, "__wrapped__"):
+                    # Get the main obj in case of it being wrapped
+                    obj = inspect.unwrap(obj)
+
+                # Type ignored because this is a private function.
+                return super()._find_lineno(  # type:ignore[misc]
+                    obj,
+                    source_lines,
+                )
+
+            def _find(
+                self, tests, obj, name, module, source_lines, globs, seen
+            ) -> None:
+                if _is_mocked(obj):
+                    return
+                with _patch_unwrap_mock_aware():
+
+                    # Type ignored because this is a private function.
+                    super()._find(  # type:ignore[misc]
+                        tests, obj, name, module, source_lines, globs, seen
+                    )
+
+        if self.path.name == "conftest.py":
+            if int(pytest.__version__.split(".")[0]) < 7:
+                module = self.config.pluginmanager._importconftest(
+                    self.path,
+                    self.config.getoption("importmode"),
+                )
+            else:
+                module = self.config.pluginmanager._importconftest(
+                    self.path,
+                    self.config.getoption("importmode"),
+                    rootpath=self.config.rootpath,
+                )
+        else:
+            try:
+                module = import_path(self.path, root=self.config.rootpath)
+            except ImportError:
+                if self.config.getvalue("ipdoctest_ignore_import_errors"):
+                    pytest.skip("unable to import module %r" % self.path)
+                else:
+                    raise
+        # Uses internal doctest module parsing mechanism.
+        finder = MockAwareDocTestFinder(parser=IPDocTestParser())
+        optionflags = get_optionflags(self)
+        runner = _get_runner(
+            verbose=False,
+            optionflags=optionflags,
+            checker=_get_checker(),
+            continue_on_failure=_get_continue_on_failure(self.config),
+        )
+
+        for test in finder.find(module, module.__name__):
+            if test.examples:  # skip empty ipdoctests
+                yield IPDoctestItem.from_parent(
+                    self, name=test.name, runner=runner, dtest=test
+                )
+
+    if int(pytest.__version__.split(".")[0]) < 7:
+
+        @property
+        def path(self) -> Path:
+            return Path(self.fspath)
+
+        @classmethod
+        def from_parent(
+            cls,
+            parent,
+            *,
+            fspath=None,
+            path: Optional[Path] = None,
+            **kw,
+        ):
+            if path is not None:
+                import py.path
+
+                fspath = py.path.local(path)
+            return super().from_parent(parent=parent, fspath=fspath, **kw)
+
+
+def _setup_fixtures(doctest_item: IPDoctestItem) -> FixtureRequest:
+    """Used by IPDoctestTextfile and IPDoctestItem to setup fixture information."""
+
+    def func() -> None:
+        pass
+
+    doctest_item.funcargs = {}  # type: ignore[attr-defined]
+    fm = doctest_item.session._fixturemanager
+    doctest_item._fixtureinfo = fm.getfixtureinfo(  # type: ignore[attr-defined]
+        node=doctest_item, func=func, cls=None, funcargs=False
+    )
+    fixture_request = FixtureRequest(doctest_item, _ispytest=True)
+    fixture_request._fillfixtures()
+    return fixture_request
+
+
+def _init_checker_class() -> Type["IPDoctestOutputChecker"]:
+    import doctest
+    import re
+    from .ipdoctest import IPDoctestOutputChecker
+
+    class LiteralsOutputChecker(IPDoctestOutputChecker):
+        # Based on doctest_nose_plugin.py from the nltk project
+        # (https://github.com/nltk/nltk) and on the "numtest" doctest extension
+        # by Sebastien Boisgerault (https://github.com/boisgera/numtest).
+
+        _unicode_literal_re = re.compile(r"(\W|^)[uU]([rR]?[\'\"])", re.UNICODE)
+        _bytes_literal_re = re.compile(r"(\W|^)[bB]([rR]?[\'\"])", re.UNICODE)
+        _number_re = re.compile(
+            r"""
+            (?P<number>
+              (?P<mantissa>
+                (?P<integer1> [+-]?\d*)\.(?P<fraction>\d+)
+                |
+                (?P<integer2> [+-]?\d+)\.
+              )
+              (?:
+                [Ee]
+                (?P<exponent1> [+-]?\d+)
+              )?
+              |
+              (?P<integer3> [+-]?\d+)
+              (?:
+                [Ee]
+                (?P<exponent2> [+-]?\d+)
+              )
+            )
+            """,
+            re.VERBOSE,
+        )
+
+        def check_output(self, want: str, got: str, optionflags: int) -> bool:
+            if super().check_output(want, got, optionflags):
+                return True
+
+            allow_unicode = optionflags & _get_allow_unicode_flag()
+            allow_bytes = optionflags & _get_allow_bytes_flag()
+            allow_number = optionflags & _get_number_flag()
+
+            if not allow_unicode and not allow_bytes and not allow_number:
+                return False
+
+            def remove_prefixes(regex: Pattern[str], txt: str) -> str:
+                return re.sub(regex, r"\1\2", txt)
+
+            if allow_unicode:
+                want = remove_prefixes(self._unicode_literal_re, want)
+                got = remove_prefixes(self._unicode_literal_re, got)
+
+            if allow_bytes:
+                want = remove_prefixes(self._bytes_literal_re, want)
+                got = remove_prefixes(self._bytes_literal_re, got)
+
+            if allow_number:
+                got = self._remove_unwanted_precision(want, got)
+
+            return super().check_output(want, got, optionflags)
+
+        def _remove_unwanted_precision(self, want: str, got: str) -> str:
+            wants = list(self._number_re.finditer(want))
+            gots = list(self._number_re.finditer(got))
+            if len(wants) != len(gots):
+                return got
+            offset = 0
+            for w, g in zip(wants, gots):
+                fraction: Optional[str] = w.group("fraction")
+                exponent: Optional[str] = w.group("exponent1")
+                if exponent is None:
+                    exponent = w.group("exponent2")
+                precision = 0 if fraction is None else len(fraction)
+                if exponent is not None:
+                    precision -= int(exponent)
+                if float(w.group()) == approx(float(g.group()), abs=10 ** -precision):
+                    # They're close enough. Replace the text we actually
+                    # got with the text we want, so that it will match when we
+                    # check the string literally.
+                    got = (
+                        got[: g.start() + offset] + w.group() + got[g.end() + offset :]
+                    )
+                    offset += w.end() - w.start() - (g.end() - g.start())
+            return got
+
+    return LiteralsOutputChecker
+
+
+def _get_checker() -> "IPDoctestOutputChecker":
+    """Return a IPDoctestOutputChecker subclass that supports some
+    additional options:
+
+    * ALLOW_UNICODE and ALLOW_BYTES options to ignore u'' and b''
+      prefixes (respectively) in string literals. Useful when the same
+      ipdoctest should run in Python 2 and Python 3.
+
+    * NUMBER to ignore floating-point differences smaller than the
+      precision of the literal number in the ipdoctest.
+
+    An inner class is used to avoid importing "ipdoctest" at the module
+    level.
+    """
+    global CHECKER_CLASS
+    if CHECKER_CLASS is None:
+        CHECKER_CLASS = _init_checker_class()
+    return CHECKER_CLASS()
+
+
+def _get_allow_unicode_flag() -> int:
+    """Register and return the ALLOW_UNICODE flag."""
+    import doctest
+
+    return doctest.register_optionflag("ALLOW_UNICODE")
+
+
+def _get_allow_bytes_flag() -> int:
+    """Register and return the ALLOW_BYTES flag."""
+    import doctest
+
+    return doctest.register_optionflag("ALLOW_BYTES")
+
+
+def _get_number_flag() -> int:
+    """Register and return the NUMBER flag."""
+    import doctest
+
+    return doctest.register_optionflag("NUMBER")
+
+
+def _get_report_choice(key: str) -> int:
+    """Return the actual `ipdoctest` module flag value.
+
+    We want to do it as late as possible to avoid importing `ipdoctest` and all
+    its dependencies when parsing options, as it adds overhead and breaks tests.
+    """
+    import doctest
+
+    return {
+        DOCTEST_REPORT_CHOICE_UDIFF: doctest.REPORT_UDIFF,
+        DOCTEST_REPORT_CHOICE_CDIFF: doctest.REPORT_CDIFF,
+        DOCTEST_REPORT_CHOICE_NDIFF: doctest.REPORT_NDIFF,
+        DOCTEST_REPORT_CHOICE_ONLY_FIRST_FAILURE: doctest.REPORT_ONLY_FIRST_FAILURE,
+        DOCTEST_REPORT_CHOICE_NONE: 0,
+    }[key]
+
+
+@pytest.fixture(scope="session")
+def ipdoctest_namespace() -> Dict[str, Any]:
+    """Fixture that returns a :py:class:`dict` that will be injected into the
+    namespace of ipdoctests."""
+    return dict()
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/show_refs.py b/contrib/python/ipython/py3/IPython/testing/plugin/show_refs.py
deleted file mode 100644
index b2c70adfc1..0000000000
--- a/contrib/python/ipython/py3/IPython/testing/plugin/show_refs.py
+++ /dev/null
@@ -1,19 +0,0 @@
-"""Simple script to show reference holding behavior.
-
-This is used by a companion test case.
-"""
-
-import gc
-
-class C(object):
-   def __del__(self):
-      pass
-      #print 'deleting object...'  # dbg
-
-if __name__ == '__main__':
-   c = C()
-
-   c_refs = gc.get_referrers(c)
-   ref_ids = list(map(id,c_refs))
-
-   print('c referrers:',list(map(type,c_refs)))
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/simple.py b/contrib/python/ipython/py3/IPython/testing/plugin/simple.py
index 3861977cab..35fbfd2fbd 100644
--- a/contrib/python/ipython/py3/IPython/testing/plugin/simple.py
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/simple.py
@@ -1,7 +1,7 @@
 """Simple example using doctests.
 
 This file just contains doctests both using plain python and IPython prompts.
-All tests should be loaded by nose.
+All tests should be loaded by Pytest.
 """
 
 def pyfunc():
@@ -24,10 +24,21 @@ def pyfunc():
     return 'pyfunc'
 
 
-def ipyfunc2():
-    """Some pure python tests...
+def ipyfunc():
+    """Some IPython tests...
+
+    In [1]: ipyfunc()
+    Out[1]: 'ipyfunc'
+
+    In [2]: import os
+
+    In [3]: 2+3
+    Out[3]: 5
 
-    >>> 1+1
-    2
+    In [4]: for i in range(3):
+       ...:     print(i, end=' ')
+       ...:     print(i+1, end=' ')
+       ...:
+    Out[4]: 0 1 1 2 2 3
     """
-    return 'pyfunc2'
+    return "ipyfunc"
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/test_exampleip.txt b/contrib/python/ipython/py3/IPython/testing/plugin/test_exampleip.txt
index 8afcbfdf7d..96b1eae19f 100644
--- a/contrib/python/ipython/py3/IPython/testing/plugin/test_exampleip.txt
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/test_exampleip.txt
@@ -21,7 +21,7 @@ Another example::
 
 Just like in IPython docstrings, you can use all IPython syntax and features::
 
-    In [9]: !echo "hello"
+    In [9]: !echo hello
     hello
 
     In [10]: a='hi'
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/test_ipdoctest.py b/contrib/python/ipython/py3/IPython/testing/plugin/test_ipdoctest.py
index d8f5991636..2686172bb2 100644
--- a/contrib/python/ipython/py3/IPython/testing/plugin/test_ipdoctest.py
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/test_ipdoctest.py
@@ -74,3 +74,19 @@ def doctest_multiline3():
     In [15]: h(0)
     Out[15]: -1
    """
+
+
+def doctest_builtin_underscore():
+    """Defining builtins._ should not break anything outside the doctest
+    while also should be working as expected inside the doctest.
+
+    In [1]: import builtins
+
+    In [2]: builtins._ = 42
+
+    In [3]: builtins._
+    Out[3]: 42
+
+    In [4]: _
+    Out[4]: 42
+    """
diff --git a/contrib/python/ipython/py3/IPython/testing/plugin/test_refs.py b/contrib/python/ipython/py3/IPython/testing/plugin/test_refs.py
index bd7ad8fb3e..b92448be07 100644
--- a/contrib/python/ipython/py3/IPython/testing/plugin/test_refs.py
+++ b/contrib/python/ipython/py3/IPython/testing/plugin/test_refs.py
@@ -37,10 +37,3 @@ def doctest_ivars():
     In [6]: zz
     Out[6]: 1
     """
-
-def doctest_refs():
-    """DocTest reference holding issues when running scripts.
-
-    In [32]: run show_refs.py
-    c referrers: [<... 'dict'>]
-    """