Python code coverage for Lib/warnings.py

#	count	content
1	n/a	"""Python part of the warnings subsystem."""
2	n/a
3	n/a	import sys
4	n/a
5	n/a
6	n/a	__all__ = ["warn", "warn_explicit", "showwarning",
7	n/a	"formatwarning", "filterwarnings", "simplefilter",
8	n/a	"resetwarnings", "catch_warnings"]
9	n/a
10	n/a	def showwarning(message, category, filename, lineno, file=None, line=None):
11	n/a	"""Hook to write a warning to a file; replace if you like."""
12	n/a	msg = WarningMessage(message, category, filename, lineno, file, line)
13	n/a	_showwarnmsg_impl(msg)
14	n/a
15	n/a	def formatwarning(message, category, filename, lineno, line=None):
16	n/a	"""Function to format a warning the standard way."""
17	n/a	msg = WarningMessage(message, category, filename, lineno, None, line)
18	n/a	return _formatwarnmsg_impl(msg)
19	n/a
20	n/a	def _showwarnmsg_impl(msg):
21	n/a	file = msg.file
22	n/a	if file is None:
23	n/a	file = sys.stderr
24	n/a	if file is None:
25	n/a	# sys.stderr is None when run with pythonw.exe:
26	n/a	# warnings get lost
27	n/a	return
28	n/a	text = _formatwarnmsg(msg)
29	n/a	try:
30	n/a	file.write(text)
31	n/a	except OSError:
32	n/a	# the file (probably stderr) is invalid - this warning gets lost.
33	n/a	pass
34	n/a
35	n/a	def _formatwarnmsg_impl(msg):
36	n/a	s = ("%s:%s: %s: %s\n"
37	n/a	% (msg.filename, msg.lineno, msg.category.__name__,
38	n/a	msg.message))
39	n/a
40	n/a	if msg.line is None:
41	n/a	try:
42	n/a	import linecache
43	n/a	line = linecache.getline(msg.filename, msg.lineno)
44	n/a	except Exception:
45	n/a	# When a warning is logged during Python shutdown, linecache
46	n/a	# and the import machinery don't work anymore
47	n/a	line = None
48	n/a	linecache = None
49	n/a	else:
50	n/a	line = msg.line
51	n/a	if line:
52	n/a	line = line.strip()
53	n/a	s += " %s\n" % line
54	n/a
55	n/a	if msg.source is not None:
56	n/a	try:
57	n/a	import tracemalloc
58	n/a	tb = tracemalloc.get_object_traceback(msg.source)
59	n/a	except Exception:
60	n/a	# When a warning is logged during Python shutdown, tracemalloc
61	n/a	# and the import machinery don't work anymore
62	n/a	tb = None
63	n/a
64	n/a	if tb is not None:
65	n/a	s += 'Object allocated at (most recent call first):\n'
66	n/a	for frame in tb:
67	n/a	s += (' File "%s", lineno %s\n'
68	n/a	% (frame.filename, frame.lineno))
69	n/a
70	n/a	try:
71	n/a	if linecache is not None:
72	n/a	line = linecache.getline(frame.filename, frame.lineno)
73	n/a	else:
74	n/a	line = None
75	n/a	except Exception:
76	n/a	line = None
77	n/a	if line:
78	n/a	line = line.strip()
79	n/a	s += ' %s\n' % line
80	n/a	return s
81	n/a
82	n/a	# Keep a reference to check if the function was replaced
83	n/a	_showwarning_orig = showwarning
84	n/a
85	n/a	def _showwarnmsg(msg):
86	n/a	"""Hook to write a warning to a file; replace if you like."""
87	n/a	try:
88	n/a	sw = showwarning
89	n/a	except NameError:
90	n/a	pass
91	n/a	else:
92	n/a	if sw is not _showwarning_orig:
93	n/a	# warnings.showwarning() was replaced
94	n/a	if not callable(sw):
95	n/a	raise TypeError("warnings.showwarning() must be set to a "
96	n/a	"function or method")
97	n/a
98	n/a	sw(msg.message, msg.category, msg.filename, msg.lineno,
99	n/a	msg.file, msg.line)
100	n/a	return
101	n/a	_showwarnmsg_impl(msg)
102	n/a
103	n/a	# Keep a reference to check if the function was replaced
104	n/a	_formatwarning_orig = formatwarning
105	n/a
106	n/a	def _formatwarnmsg(msg):
107	n/a	"""Function to format a warning the standard way."""
108	n/a	try:
109	n/a	fw = formatwarning
110	n/a	except NameError:
111	n/a	pass
112	n/a	else:
113	n/a	if fw is not _formatwarning_orig:
114	n/a	# warnings.formatwarning() was replaced
115	n/a	return fw(msg.message, msg.category,
116	n/a	msg.filename, msg.lineno, line=msg.line)
117	n/a	return _formatwarnmsg_impl(msg)
118	n/a
119	n/a	def filterwarnings(action, message="", category=Warning, module="", lineno=0,
120	n/a	append=False):
121	n/a	"""Insert an entry into the list of warnings filters (at the front).
122	n/a
123	n/a	'action' -- one of "error", "ignore", "always", "default", "module",
124	n/a	or "once"
125	n/a	'message' -- a regex that the warning message must match
126	n/a	'category' -- a class that the warning must be a subclass of
127	n/a	'module' -- a regex that the module name must match
128	n/a	'lineno' -- an integer line number, 0 matches all warnings
129	n/a	'append' -- if true, append to the list of filters
130	n/a	"""
131	n/a	import re
132	n/a	assert action in ("error", "ignore", "always", "default", "module",
133	n/a	"once"), "invalid action: %r" % (action,)
134	n/a	assert isinstance(message, str), "message must be a string"
135	n/a	assert isinstance(category, type), "category must be a class"
136	n/a	assert issubclass(category, Warning), "category must be a Warning subclass"
137	n/a	assert isinstance(module, str), "module must be a string"
138	n/a	assert isinstance(lineno, int) and lineno >= 0, \
139	n/a	"lineno must be an int >= 0"
140	n/a	_add_filter(action, re.compile(message, re.I), category,
141	n/a	re.compile(module), lineno, append=append)
142	n/a
143	n/a	def simplefilter(action, category=Warning, lineno=0, append=False):
144	n/a	"""Insert a simple entry into the list of warnings filters (at the front).
145	n/a
146	n/a	A simple filter matches all modules and messages.
147	n/a	'action' -- one of "error", "ignore", "always", "default", "module",
148	n/a	or "once"
149	n/a	'category' -- a class that the warning must be a subclass of
150	n/a	'lineno' -- an integer line number, 0 matches all warnings
151	n/a	'append' -- if true, append to the list of filters
152	n/a	"""
153	n/a	assert action in ("error", "ignore", "always", "default", "module",
154	n/a	"once"), "invalid action: %r" % (action,)
155	n/a	assert isinstance(lineno, int) and lineno >= 0, \
156	n/a	"lineno must be an int >= 0"
157	n/a	_add_filter(action, None, category, None, lineno, append=append)
158	n/a
159	n/a	def _add_filter(*item, append):
160	n/a	# Remove possible duplicate filters, so new one will be placed
161	n/a	# in correct place. If append=True and duplicate exists, do nothing.
162	n/a	if not append:
163	n/a	try:
164	n/a	filters.remove(item)
165	n/a	except ValueError:
166	n/a	pass
167	n/a	filters.insert(0, item)
168	n/a	else:
169	n/a	if item not in filters:
170	n/a	filters.append(item)
171	n/a	_filters_mutated()
172	n/a
173	n/a	def resetwarnings():
174	n/a	"""Clear the list of warning filters, so that no filters are active."""
175	n/a	filters[:] = []
176	n/a	_filters_mutated()
177	n/a
178	n/a	class _OptionError(Exception):
179	n/a	"""Exception used by option processing helpers."""
180	n/a	pass
181	n/a
182	n/a	# Helper to process -W options passed via sys.warnoptions
183	n/a	def _processoptions(args):
184	n/a	for arg in args:
185	n/a	try:
186	n/a	_setoption(arg)
187	n/a	except _OptionError as msg:
188	n/a	print("Invalid -W option ignored:", msg, file=sys.stderr)
189	n/a
190	n/a	# Helper for _processoptions()
191	n/a	def _setoption(arg):
192	n/a	import re
193	n/a	parts = arg.split(':')
194	n/a	if len(parts) > 5:
195	n/a	raise _OptionError("too many fields (max 5): %r" % (arg,))
196	n/a	while len(parts) < 5:
197	n/a	parts.append('')
198	n/a	action, message, category, module, lineno = [s.strip()
199	n/a	for s in parts]
200	n/a	action = _getaction(action)
201	n/a	message = re.escape(message)
202	n/a	category = _getcategory(category)
203	n/a	module = re.escape(module)
204	n/a	if module:
205	n/a	module = module + '$'
206	n/a	if lineno:
207	n/a	try:
208	n/a	lineno = int(lineno)
209	n/a	if lineno < 0:
210	n/a	raise ValueError
211	n/a	except (ValueError, OverflowError):
212	n/a	raise _OptionError("invalid lineno %r" % (lineno,))
213	n/a	else:
214	n/a	lineno = 0
215	n/a	filterwarnings(action, message, category, module, lineno)
216	n/a
217	n/a	# Helper for _setoption()
218	n/a	def _getaction(action):
219	n/a	if not action:
220	n/a	return "default"
221	n/a	if action == "all": return "always" # Alias
222	n/a	for a in ('default', 'always', 'ignore', 'module', 'once', 'error'):
223	n/a	if a.startswith(action):
224	n/a	return a
225	n/a	raise _OptionError("invalid action: %r" % (action,))
226	n/a
227	n/a	# Helper for _setoption()
228	n/a	def _getcategory(category):
229	n/a	import re
230	n/a	if not category:
231	n/a	return Warning
232	n/a	if re.match("^[a-zA-Z0-9_]+$", category):
233	n/a	try:
234	n/a	cat = eval(category)
235	n/a	except NameError:
236	n/a	raise _OptionError("unknown warning category: %r" % (category,))
237	n/a	else:
238	n/a	i = category.rfind(".")
239	n/a	module = category[:i]
240	n/a	klass = category[i+1:]
241	n/a	try:
242	n/a	m = __import__(module, None, None, [klass])
243	n/a	except ImportError:
244	n/a	raise _OptionError("invalid module name: %r" % (module,))
245	n/a	try:
246	n/a	cat = getattr(m, klass)
247	n/a	except AttributeError:
248	n/a	raise _OptionError("unknown warning category: %r" % (category,))
249	n/a	if not issubclass(cat, Warning):
250	n/a	raise _OptionError("invalid warning category: %r" % (category,))
251	n/a	return cat
252	n/a
253	n/a
254	n/a	def _is_internal_frame(frame):
255	n/a	"""Signal whether the frame is an internal CPython implementation detail."""
256	n/a	filename = frame.f_code.co_filename
257	n/a	return 'importlib' in filename and '_bootstrap' in filename
258	n/a
259	n/a
260	n/a	def _next_external_frame(frame):
261	n/a	"""Find the next frame that doesn't involve CPython internals."""
262	n/a	frame = frame.f_back
263	n/a	while frame is not None and _is_internal_frame(frame):
264	n/a	frame = frame.f_back
265	n/a	return frame
266	n/a
267	n/a
268	n/a	# Code typically replaced by _warnings
269	n/a	def warn(message, category=None, stacklevel=1, source=None):
270	n/a	"""Issue a warning, or maybe ignore it or raise an exception."""
271	n/a	# Check if message is already a Warning object
272	n/a	if isinstance(message, Warning):
273	n/a	category = message.__class__
274	n/a	# Check category argument
275	n/a	if category is None:
276	n/a	category = UserWarning
277	n/a	if not (isinstance(category, type) and issubclass(category, Warning)):
278	n/a	raise TypeError("category must be a Warning subclass, "
279	n/a	"not '{:s}'".format(type(category).__name__))
280	n/a	# Get context information
281	n/a	try:
282	n/a	if stacklevel <= 1 or _is_internal_frame(sys._getframe(1)):
283	n/a	# If frame is too small to care or if the warning originated in
284	n/a	# internal code, then do not try to hide any frames.
285	n/a	frame = sys._getframe(stacklevel)
286	n/a	else:
287	n/a	frame = sys._getframe(1)
288	n/a	# Look for one frame less since the above line starts us off.
289	n/a	for x in range(stacklevel-1):
290	n/a	frame = _next_external_frame(frame)
291	n/a	if frame is None:
292	n/a	raise ValueError
293	n/a	except ValueError:
294	n/a	globals = sys.__dict__
295	n/a	lineno = 1
296	n/a	else:
297	n/a	globals = frame.f_globals
298	n/a	lineno = frame.f_lineno
299	n/a	if '__name__' in globals:
300	n/a	module = globals['__name__']
301	n/a	else:
302	n/a	module = "<string>"
303	n/a	filename = globals.get('__file__')
304	n/a	if filename:
305	n/a	fnl = filename.lower()
306	n/a	if fnl.endswith(".pyc"):
307	n/a	filename = filename[:-1]
308	n/a	else:
309	n/a	if module == "__main__":
310	n/a	try:
311	n/a	filename = sys.argv[0]
312	n/a	except AttributeError:
313	n/a	# embedded interpreters don't have sys.argv, see bug #839151
314	n/a	filename = '__main__'
315	n/a	if not filename:
316	n/a	filename = module
317	n/a	registry = globals.setdefault("__warningregistry__", {})
318	n/a	warn_explicit(message, category, filename, lineno, module, registry,
319	n/a	globals, source)
320	n/a
321	n/a	def warn_explicit(message, category, filename, lineno,
322	n/a	module=None, registry=None, module_globals=None,
323	n/a	source=None):
324	n/a	lineno = int(lineno)
325	n/a	if module is None:
326	n/a	module = filename or "<unknown>"
327	n/a	if module[-3:].lower() == ".py":
328	n/a	module = module[:-3] # XXX What about leading pathname?
329	n/a	if registry is None:
330	n/a	registry = {}
331	n/a	if registry.get('version', 0) != _filters_version:
332	n/a	registry.clear()
333	n/a	registry['version'] = _filters_version
334	n/a	if isinstance(message, Warning):
335	n/a	text = str(message)
336	n/a	category = message.__class__
337	n/a	else:
338	n/a	text = message
339	n/a	message = category(message)
340	n/a	key = (text, category, lineno)
341	n/a	# Quick test for common case
342	n/a	if registry.get(key):
343	n/a	return
344	n/a	# Search the filters
345	n/a	for item in filters:
346	n/a	action, msg, cat, mod, ln = item
347	n/a	if ((msg is None or msg.match(text)) and
348	n/a	issubclass(category, cat) and
349	n/a	(mod is None or mod.match(module)) and
350	n/a	(ln == 0 or lineno == ln)):
351	n/a	break
352	n/a	else:
353	n/a	action = defaultaction
354	n/a	# Early exit actions
355	n/a	if action == "ignore":
356	n/a	registry[key] = 1
357	n/a	return
358	n/a
359	n/a	# Prime the linecache for formatting, in case the
360	n/a	# "file" is actually in a zipfile or something.
361	n/a	import linecache
362	n/a	linecache.getlines(filename, module_globals)
363	n/a
364	n/a	if action == "error":
365	n/a	raise message
366	n/a	# Other actions
367	n/a	if action == "once":
368	n/a	registry[key] = 1
369	n/a	oncekey = (text, category)
370	n/a	if onceregistry.get(oncekey):
371	n/a	return
372	n/a	onceregistry[oncekey] = 1
373	n/a	elif action == "always":
374	n/a	pass
375	n/a	elif action == "module":
376	n/a	registry[key] = 1
377	n/a	altkey = (text, category, 0)
378	n/a	if registry.get(altkey):
379	n/a	return
380	n/a	registry[altkey] = 1
381	n/a	elif action == "default":
382	n/a	registry[key] = 1
383	n/a	else:
384	n/a	# Unrecognized actions are errors
385	n/a	raise RuntimeError(
386	n/a	"Unrecognized action (%r) in warnings.filters:\n %s" %
387	n/a	(action, item))
388	n/a	# Print message and context
389	n/a	msg = WarningMessage(message, category, filename, lineno, source)
390	n/a	_showwarnmsg(msg)
391	n/a
392	n/a
393	n/a	class WarningMessage(object):
394	n/a
395	n/a	_WARNING_DETAILS = ("message", "category", "filename", "lineno", "file",
396	n/a	"line", "source")
397	n/a
398	n/a	def __init__(self, message, category, filename, lineno, file=None,
399	n/a	line=None, source=None):
400	n/a	local_values = locals()
401	n/a	for attr in self._WARNING_DETAILS:
402	n/a	setattr(self, attr, local_values[attr])
403	n/a	self._category_name = category.__name__ if category else None
404	n/a
405	n/a	def __str__(self):
406	n/a	return ("{message : %r, category : %r, filename : %r, lineno : %s, "
407	n/a	"line : %r}" % (self.message, self._category_name,
408	n/a	self.filename, self.lineno, self.line))
409	n/a
410	n/a
411	n/a	class catch_warnings(object):
412	n/a
413	n/a	"""A context manager that copies and restores the warnings filter upon
414	n/a	exiting the context.
415	n/a
416	n/a	The 'record' argument specifies whether warnings should be captured by a
417	n/a	custom implementation of warnings.showwarning() and be appended to a list
418	n/a	returned by the context manager. Otherwise None is returned by the context
419	n/a	manager. The objects appended to the list are arguments whose attributes
420	n/a	mirror the arguments to showwarning().
421	n/a
422	n/a	The 'module' argument is to specify an alternative module to the module
423	n/a	named 'warnings' and imported under that name. This argument is only useful
424	n/a	when testing the warnings module itself.
425	n/a
426	n/a	"""
427	n/a
428	n/a	def __init__(self, *, record=False, module=None):
429	n/a	"""Specify whether to record warnings and if an alternative module
430	n/a	should be used other than sys.modules['warnings'].
431	n/a
432	n/a	For compatibility with Python 3.0, please consider all arguments to be
433	n/a	keyword-only.
434	n/a
435	n/a	"""
436	n/a	self._record = record
437	n/a	self._module = sys.modules['warnings'] if module is None else module
438	n/a	self._entered = False
439	n/a
440	n/a	def __repr__(self):
441	n/a	args = []
442	n/a	if self._record:
443	n/a	args.append("record=True")
444	n/a	if self._module is not sys.modules['warnings']:
445	n/a	args.append("module=%r" % self._module)
446	n/a	name = type(self).__name__
447	n/a	return "%s(%s)" % (name, ", ".join(args))
448	n/a
449	n/a	def __enter__(self):
450	n/a	if self._entered:
451	n/a	raise RuntimeError("Cannot enter %r twice" % self)
452	n/a	self._entered = True
453	n/a	self._filters = self._module.filters
454	n/a	self._module.filters = self._filters[:]
455	n/a	self._module._filters_mutated()
456	n/a	self._showwarning = self._module.showwarning
457	n/a	self._showwarnmsg_impl = self._module._showwarnmsg_impl
458	n/a	if self._record:
459	n/a	log = []
460	n/a	self._module._showwarnmsg_impl = log.append
461	n/a	# Reset showwarning() to the default implementation to make sure
462	n/a	# that _showwarnmsg() calls _showwarnmsg_impl()
463	n/a	self._module.showwarning = self._module._showwarning_orig
464	n/a	return log
465	n/a	else:
466	n/a	return None
467	n/a
468	n/a	def __exit__(self, *exc_info):
469	n/a	if not self._entered:
470	n/a	raise RuntimeError("Cannot exit %r without entering first" % self)
471	n/a	self._module.filters = self._filters
472	n/a	self._module._filters_mutated()
473	n/a	self._module.showwarning = self._showwarning
474	n/a	self._module._showwarnmsg_impl = self._showwarnmsg_impl
475	n/a
476	n/a
477	n/a	# filters contains a sequence of filter 5-tuples
478	n/a	# The components of the 5-tuple are:
479	n/a	# - an action: error, ignore, always, default, module, or once
480	n/a	# - a compiled regex that must match the warning message
481	n/a	# - a class representing the warning category
482	n/a	# - a compiled regex that must match the module that is being warned
483	n/a	# - a line number for the line being warning, or 0 to mean any line
484	n/a	# If either if the compiled regexs are None, match anything.
485	n/a	_warnings_defaults = False
486	n/a	try:
487	n/a	from _warnings import (filters, _defaultaction, _onceregistry,
488	n/a	warn, warn_explicit, _filters_mutated)
489	n/a	defaultaction = _defaultaction
490	n/a	onceregistry = _onceregistry
491	n/a	_warnings_defaults = True
492	n/a	except ImportError:
493	n/a	filters = []
494	n/a	defaultaction = "default"
495	n/a	onceregistry = {}
496	n/a
497	n/a	_filters_version = 1
498	n/a
499	n/a	def _filters_mutated():
500	n/a	global _filters_version
501	n/a	_filters_version += 1
502	n/a
503	n/a
504	n/a	# Module initialization
505	n/a	_processoptions(sys.warnoptions)
506	n/a	if not _warnings_defaults:
507	n/a	silence = [ImportWarning, PendingDeprecationWarning]
508	n/a	silence.append(DeprecationWarning)
509	n/a	for cls in silence:
510	n/a	simplefilter("ignore", category=cls)
511	n/a	bytes_warning = sys.flags.bytes_warning
512	n/a	if bytes_warning > 1:
513	n/a	bytes_action = "error"
514	n/a	elif bytes_warning:
515	n/a	bytes_action = "default"
516	n/a	else:
517	n/a	bytes_action = "ignore"
518	n/a	simplefilter(bytes_action, category=BytesWarning, append=1)
519	n/a	# resource usage warnings are enabled by default in pydebug mode
520	n/a	if hasattr(sys, 'gettotalrefcount'):
521	n/a	resource_action = "always"
522	n/a	else:
523	n/a	resource_action = "ignore"
524	n/a	simplefilter(resource_action, category=ResourceWarning, append=1)
525	n/a
526	n/a	del _warnings_defaults