intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 33 insertions, 0 deletions

diff --git a/contrib/python/PyYAML/py3/_yaml/__init__.py b/contrib/python/PyYAML/py3/_yaml/__init__.py
new file mode 100644
index 0000000000..7baa8c4b68
--- /dev/null
+++ b/contrib/python/PyYAML/py3/_yaml/__init__.py
@@ -0,0 +1,33 @@
+# This is a stub package designed to roughly emulate the _yaml
+# extension module, which previously existed as a standalone module
+# and has been moved into the `yaml` package namespace.
+# It does not perfectly mimic its old counterpart, but should get
+# close enough for anyone who's relying on it even when they shouldn't.
+import yaml
+
+# in some circumstances, the yaml module we imoprted may be from a different version, so we need
+# to tread carefully when poking at it here (it may not have the attributes we expect)
+if not getattr(yaml, '__with_libyaml__', False):
+    from sys import version_info
+
+    exc = ModuleNotFoundError if version_info >= (3, 6) else ImportError
+    raise exc("No module named '_yaml'")
+else:
+    from yaml._yaml import *
+    import warnings
+    warnings.warn(
+        'The _yaml extension module is now located at yaml._yaml'
+        ' and its location is subject to change.  To use the'
+        ' LibYAML-based parser and emitter, import from `yaml`:'
+        ' `from yaml import CLoader as Loader, CDumper as Dumper`.',
+        DeprecationWarning
+    )
+    del warnings
+    # Don't `del yaml` here because yaml is actually an existing
+    # namespace member of _yaml.
+
+__name__ = '_yaml'
+# If the module is top-level (i.e. not a part of any specific package)
+# then the attribute should be set to ''.
+# https://docs.python.org/3.8/library/types.html
+__package__ = ''