1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
"""
Tools to open .py files as Unicode, using the encoding specified within the file,
as per PEP 263.
Much of the code is taken from the tokenize module in Python 3.2.
"""
from __future__ import absolute_import
import io
from io import TextIOWrapper, BytesIO
import os.path
import re
from .py3compat import unicode_type
cookie_re = re.compile(r"coding[:=]\s*([-\w.]+)", re.UNICODE)
cookie_comment_re = re.compile(r"^\s*#.*coding[:=]\s*([-\w.]+)", re.UNICODE)
try:
# Available in Python 3
from tokenize import detect_encoding
except ImportError:
from codecs import lookup, BOM_UTF8
# Copied from Python 3.2 tokenize
def _get_normal_name(orig_enc):
"""Imitates get_normal_name in tokenizer.c."""
# Only care about the first 12 characters.
enc = orig_enc[:12].lower().replace("_", "-")
if enc == "utf-8" or enc.startswith("utf-8-"):
return "utf-8"
if enc in ("latin-1", "iso-8859-1", "iso-latin-1") or \
enc.startswith(("latin-1-", "iso-8859-1-", "iso-latin-1-")):
return "iso-8859-1"
return orig_enc
# Copied from Python 3.2 tokenize
def detect_encoding(readline):
"""
The detect_encoding() function is used to detect the encoding that should
be used to decode a Python source file. It requires one argment, readline,
in the same way as the tokenize() generator.
It will call readline a maximum of twice, and return the encoding used
(as a string) and a list of any lines (left as bytes) it has read in.
It detects the encoding from the presence of a utf-8 bom or an encoding
cookie as specified in pep-0263. If both a bom and a cookie are present,
but disagree, a SyntaxError will be raised. If the encoding cookie is an
invalid charset, raise a SyntaxError. Note that if a utf-8 bom is found,
'utf-8-sig' is returned.
If no encoding is specified, then the default of 'utf-8' will be returned.
"""
bom_found = False
encoding = None
default = 'utf-8'
def read_or_stop():
try:
return readline()
except StopIteration:
return b''
def find_cookie(line):
try:
line_string = line.decode('ascii')
except UnicodeDecodeError:
return None
matches = cookie_re.findall(line_string)
if not matches:
return None
encoding = _get_normal_name(matches[0])
try:
codec = lookup(encoding)
except LookupError:
# This behaviour mimics the Python interpreter
raise SyntaxError("unknown encoding: " + encoding)
if bom_found:
if codec.name != 'utf-8':
# This behaviour mimics the Python interpreter
raise SyntaxError('encoding problem: utf-8')
encoding += '-sig'
return encoding
first = read_or_stop()
if first.startswith(BOM_UTF8):
bom_found = True
first = first[3:]
default = 'utf-8-sig'
if not first:
return default, []
encoding = find_cookie(first)
if encoding:
return encoding, [first]
second = read_or_stop()
if not second:
return default, [first]
encoding = find_cookie(second)
if encoding:
return encoding, [first, second]
return default, [first, second]
try:
# Available in Python 3.2 and above.
from tokenize import open
except ImportError:
# Copied from Python 3.2 tokenize
def open(filename):
"""Open a file in read only mode using the encoding detected by
detect_encoding().
"""
buffer = io.open(filename, 'rb') # Tweaked to use io.open for Python 2
encoding, lines = detect_encoding(buffer.readline)
buffer.seek(0)
text = TextIOWrapper(buffer, encoding, line_buffering=True)
text.mode = 'r'
return text
def source_to_unicode(txt, errors='replace', skip_encoding_cookie=True):
"""Converts a bytes string with python source code to unicode.
Unicode strings are passed through unchanged. Byte strings are checked
for the python source file encoding cookie to determine encoding.
txt can be either a bytes buffer or a string containing the source
code.
"""
if isinstance(txt, unicode_type):
return txt
if isinstance(txt, bytes):
buffer = BytesIO(txt)
else:
buffer = txt
try:
encoding, _ = detect_encoding(buffer.readline)
except SyntaxError:
encoding = "ascii"
buffer.seek(0)
text = TextIOWrapper(buffer, encoding, errors=errors, line_buffering=True)
text.mode = 'r'
if skip_encoding_cookie:
return u"".join(strip_encoding_cookie(text))
else:
return text.read()
def strip_encoding_cookie(filelike):
"""Generator to pull lines from a text-mode file, skipping the encoding
cookie if it is found in the first two lines.
"""
it = iter(filelike)
try:
first = next(it)
if not cookie_comment_re.match(first):
yield first
second = next(it)
if not cookie_comment_re.match(second):
yield second
except StopIteration:
return
for line in it:
yield line
def read_py_file(filename, skip_encoding_cookie=True):
"""Read a Python file, using the encoding declared inside the file.
Parameters
----------
filename : str
The path to the file to read.
skip_encoding_cookie : bool
If True (the default), and the encoding declaration is found in the first
two lines, that line will be excluded from the output - compiling a
unicode string with an encoding declaration is a SyntaxError in Python 2.
Returns
-------
A unicode string containing the contents of the file.
"""
with open(filename) as f: # the open function defined in this module.
if skip_encoding_cookie:
return "".join(strip_encoding_cookie(f))
else:
return f.read()
def read_py_url(url, errors='replace', skip_encoding_cookie=True):
"""Read a Python file from a URL, using the encoding declared inside the file.
Parameters
----------
url : str
The URL from which to fetch the file.
errors : str
How to handle decoding errors in the file. Options are the same as for
bytes.decode(), but here 'replace' is the default.
skip_encoding_cookie : bool
If True (the default), and the encoding declaration is found in the first
two lines, that line will be excluded from the output - compiling a
unicode string with an encoding declaration is a SyntaxError in Python 2.
Returns
-------
A unicode string containing the contents of the file.
"""
# Deferred import for faster start
try:
from urllib.request import urlopen # Py 3
except ImportError:
from urllib import urlopen
response = urlopen(url)
buffer = io.BytesIO(response.read())
return source_to_unicode(buffer, errors, skip_encoding_cookie)
def _list_readline(x):
"""Given a list, returns a readline() function that returns the next element
with each call.
"""
x = iter(x)
def readline():
return next(x)
return readline
# Code for going between .py files and cached .pyc files ----------------------
try: # Python 3.2, see PEP 3147
try:
from importlib.util import source_from_cache, cache_from_source
except ImportError :
## deprecated since 3.4
from imp import source_from_cache, cache_from_source
except ImportError:
# Python <= 3.1: .pyc files go next to .py
def source_from_cache(path):
basename, ext = os.path.splitext(path)
if ext not in ('.pyc', '.pyo'):
raise ValueError('Not a cached Python file extension', ext)
# Should we look for .pyw files?
return basename + '.py'
def cache_from_source(path, debug_override=None):
if debug_override is None:
debug_override = __debug__
basename, ext = os.path.splitext(path)
return basename + '.pyc' if debug_override else '.pyo'
|
