"""Python part of the warnings subsystem.""" | |
# Note: function level imports should *not* be used | |
# in this module as it may cause import lock deadlock. | |
# See bug 683658. | |
import linecache | |
import sys | |
import types | |
__all__ = ["warn", "showwarning", "formatwarning", "filterwarnings", | |
"resetwarnings", "catch_warnings"] | |
def warnpy3k(message, category=None, stacklevel=1): | |
"""Issue a deprecation warning for Python 3.x related changes. | |
Warnings are omitted unless Python is started with the -3 option. | |
""" | |
if sys.py3kwarning: | |
if category is None: | |
category = DeprecationWarning | |
warn(message, category, stacklevel+1) | |
def _show_warning(message, category, filename, lineno, file=None, line=None): | |
"""Hook to write a warning to a file; replace if you like.""" | |
if file is None: | |
file = sys.stderr | |
try: | |
file.write(formatwarning(message, category, filename, lineno, line)) | |
except IOError: | |
pass # the file (probably stderr) is invalid - this warning gets lost. | |
# Keep a working version around in case the deprecation of the old API is | |
# triggered. | |
showwarning = _show_warning | |
def formatwarning(message, category, filename, lineno, line=None): | |
"""Function to format a warning the standard way.""" | |
s = "%s:%s: %s: %s\n" % (filename, lineno, category.__name__, message) | |
line = linecache.getline(filename, lineno) if line is None else line | |
if line: | |
line = line.strip() | |
s += " %s\n" % line | |
return s | |
def filterwarnings(action, message="", category=Warning, module="", lineno=0, | |
append=0): | |
"""Insert an entry into the list of warnings filters (at the front). | |
'action' -- one of "error", "ignore", "always", "default", "module", | |
or "once" | |
'message' -- a regex that the warning message must match | |
'category' -- a class that the warning must be a subclass of | |
'module' -- a regex that the module name must match | |
'lineno' -- an integer line number, 0 matches all warnings | |
'append' -- if true, append to the list of filters | |
""" | |
import re | |
assert action in ("error", "ignore", "always", "default", "module", | |
"once"), "invalid action: %r" % (action,) | |
assert isinstance(message, basestring), "message must be a string" | |
assert isinstance(category, (type, types.ClassType)), \ | |
"category must be a class" | |
assert issubclass(category, Warning), "category must be a Warning subclass" | |
assert isinstance(module, basestring), "module must be a string" | |
assert isinstance(lineno, int) and lineno >= 0, \ | |
"lineno must be an int >= 0" | |
item = (action, re.compile(message, re.I), category, | |
re.compile(module), lineno) | |
if append: | |
filters.append(item) | |
else: | |
filters.insert(0, item) | |
def simplefilter(action, category=Warning, lineno=0, append=0): | |
"""Insert a simple entry into the list of warnings filters (at the front). | |
A simple filter matches all modules and messages. | |
'action' -- one of "error", "ignore", "always", "default", "module", | |
or "once" | |
'category' -- a class that the warning must be a subclass of | |
'lineno' -- an integer line number, 0 matches all warnings | |
'append' -- if true, append to the list of filters | |
""" | |
assert action in ("error", "ignore", "always", "default", "module", | |
"once"), "invalid action: %r" % (action,) | |
assert isinstance(lineno, int) and lineno >= 0, \ | |
"lineno must be an int >= 0" | |
item = (action, None, category, None, lineno) | |
if append: | |
filters.append(item) | |
else: | |
filters.insert(0, item) | |
def resetwarnings(): | |
"""Clear the list of warning filters, so that no filters are active.""" | |
filters[:] = [] | |
class _OptionError(Exception): | |
"""Exception used by option processing helpers.""" | |
pass | |
# Helper to process -W options passed via sys.warnoptions | |
def _processoptions(args): | |
for arg in args: | |
try: | |
_setoption(arg) | |
except _OptionError, msg: | |
print >>sys.stderr, "Invalid -W option ignored:", msg | |
# Helper for _processoptions() | |
def _setoption(arg): | |
import re | |
parts = arg.split(':') | |
if len(parts) > 5: | |
raise _OptionError("too many fields (max 5): %r" % (arg,)) | |
while len(parts) < 5: | |
parts.append('') | |
action, message, category, module, lineno = [s.strip() | |
for s in parts] | |
action = _getaction(action) | |
message = re.escape(message) | |
category = _getcategory(category) | |
module = re.escape(module) | |
if module: | |
module = module + '$' | |
if lineno: | |
try: | |
lineno = int(lineno) | |
if lineno < 0: | |
raise ValueError | |
except (ValueError, OverflowError): | |
raise _OptionError("invalid lineno %r" % (lineno,)) | |
else: | |
lineno = 0 | |
filterwarnings(action, message, category, module, lineno) | |
# Helper for _setoption() | |
def _getaction(action): | |
if not action: | |
return "default" | |
if action == "all": return "always" # Alias | |
for a in ('default', 'always', 'ignore', 'module', 'once', 'error'): | |
if a.startswith(action): | |
return a | |
raise _OptionError("invalid action: %r" % (action,)) | |
# Helper for _setoption() | |
def _getcategory(category): | |
import re | |
if not category: | |
return Warning | |
if re.match("^[a-zA-Z0-9_]+$", category): | |
try: | |
cat = eval(category) | |
except NameError: | |
raise _OptionError("unknown warning category: %r" % (category,)) | |
else: | |
i = category.rfind(".") | |
module = category[:i] | |
klass = category[i+1:] | |
try: | |
m = __import__(module, None, None, [klass]) | |
except ImportError: | |
raise _OptionError("invalid module name: %r" % (module,)) | |
try: | |
cat = getattr(m, klass) | |
except AttributeError: | |
raise _OptionError("unknown warning category: %r" % (category,)) | |
if not issubclass(cat, Warning): | |
raise _OptionError("invalid warning category: %r" % (category,)) | |
return cat | |
# Code typically replaced by _warnings | |
def warn(message, category=None, stacklevel=1): | |
"""Issue a warning, or maybe ignore it or raise an exception.""" | |
# Check if message is already a Warning object | |
if isinstance(message, Warning): | |
category = message.__class__ | |
# Check category argument | |
if category is None: | |
category = UserWarning | |
assert issubclass(category, Warning) | |
# Get context information | |
try: | |
caller = sys._getframe(stacklevel) | |
except ValueError: | |
globals = sys.__dict__ | |
lineno = 1 | |
else: | |
globals = caller.f_globals | |
lineno = caller.f_lineno | |
if '__name__' in globals: | |
module = globals['__name__'] | |
else: | |
module = "<string>" | |
filename = globals.get('__file__') | |
if filename: | |
fnl = filename.lower() | |
if fnl.endswith((".pyc", ".pyo")): | |
filename = filename[:-1] | |
else: | |
if module == "__main__": | |
try: | |
filename = sys.argv[0] | |
except AttributeError: | |
# embedded interpreters don't have sys.argv, see bug #839151 | |
filename = '__main__' | |
if not filename: | |
filename = module | |
registry = globals.setdefault("__warningregistry__", {}) | |
warn_explicit(message, category, filename, lineno, module, registry, | |
globals) | |
def warn_explicit(message, category, filename, lineno, | |
module=None, registry=None, module_globals=None): | |
lineno = int(lineno) | |
if module is None: | |
module = filename or "<unknown>" | |
if module[-3:].lower() == ".py": | |
module = module[:-3] # XXX What about leading pathname? | |
if registry is None: | |
registry = {} | |
if isinstance(message, Warning): | |
text = str(message) | |
category = message.__class__ | |
else: | |
text = message | |
message = category(message) | |
key = (text, category, lineno) | |
# Quick test for common case | |
if registry.get(key): | |
return | |
# Search the filters | |
for item in filters: | |
action, msg, cat, mod, ln = item | |
if ((msg is None or msg.match(text)) and | |
issubclass(category, cat) and | |
(mod is None or mod.match(module)) and | |
(ln == 0 or lineno == ln)): | |
break | |
else: | |
action = defaultaction | |
# Early exit actions | |
if action == "ignore": | |
registry[key] = 1 | |
return | |
# Prime the linecache for formatting, in case the | |
# "file" is actually in a zipfile or something. | |
linecache.getlines(filename, module_globals) | |
if action == "error": | |
raise message | |
# Other actions | |
if action == "once": | |
registry[key] = 1 | |
oncekey = (text, category) | |
if onceregistry.get(oncekey): | |
return | |
onceregistry[oncekey] = 1 | |
elif action == "always": | |
pass | |
elif action == "module": | |
registry[key] = 1 | |
altkey = (text, category, 0) | |
if registry.get(altkey): | |
return | |
registry[altkey] = 1 | |
elif action == "default": | |
registry[key] = 1 | |
else: | |
# Unrecognized actions are errors | |
raise RuntimeError( | |
"Unrecognized action (%r) in warnings.filters:\n %s" % | |
(action, item)) | |
# Print message and context | |
showwarning(message, category, filename, lineno) | |
class WarningMessage(object): | |
"""Holds the result of a single showwarning() call.""" | |
_WARNING_DETAILS = ("message", "category", "filename", "lineno", "file", | |
"line") | |
def __init__(self, message, category, filename, lineno, file=None, | |
line=None): | |
local_values = locals() | |
for attr in self._WARNING_DETAILS: | |
setattr(self, attr, local_values[attr]) | |
self._category_name = category.__name__ if category else None | |
def __str__(self): | |
return ("{message : %r, category : %r, filename : %r, lineno : %s, " | |
"line : %r}" % (self.message, self._category_name, | |
self.filename, self.lineno, self.line)) | |
class catch_warnings(object): | |
"""A context manager that copies and restores the warnings filter upon | |
exiting the context. | |
The 'record' argument specifies whether warnings should be captured by a | |
custom implementation of warnings.showwarning() and be appended to a list | |
returned by the context manager. Otherwise None is returned by the context | |
manager. The objects appended to the list are arguments whose attributes | |
mirror the arguments to showwarning(). | |
The 'module' argument is to specify an alternative module to the module | |
named 'warnings' and imported under that name. This argument is only useful | |
when testing the warnings module itself. | |
""" | |
def __init__(self, record=False, module=None): | |
"""Specify whether to record warnings and if an alternative module | |
should be used other than sys.modules['warnings']. | |
For compatibility with Python 3.0, please consider all arguments to be | |
keyword-only. | |
""" | |
self._record = record | |
self._module = sys.modules['warnings'] if module is None else module | |
self._entered = False | |
def __repr__(self): | |
args = [] | |
if self._record: | |
args.append("record=True") | |
if self._module is not sys.modules['warnings']: | |
args.append("module=%r" % self._module) | |
name = type(self).__name__ | |
return "%s(%s)" % (name, ", ".join(args)) | |
def __enter__(self): | |
if self._entered: | |
raise RuntimeError("Cannot enter %r twice" % self) | |
self._entered = True | |
self._filters = self._module.filters | |
self._module.filters = self._filters[:] | |
self._showwarning = self._module.showwarning | |
if self._record: | |
log = [] | |
def showwarning(*args, **kwargs): | |
log.append(WarningMessage(*args, **kwargs)) | |
self._module.showwarning = showwarning | |
return log | |
else: | |
return None | |
def __exit__(self, *exc_info): | |
if not self._entered: | |
raise RuntimeError("Cannot exit %r without entering first" % self) | |
self._module.filters = self._filters | |
self._module.showwarning = self._showwarning | |
# filters contains a sequence of filter 5-tuples | |
# The components of the 5-tuple are: | |
# - an action: error, ignore, always, default, module, or once | |
# - a compiled regex that must match the warning message | |
# - a class representing the warning category | |
# - a compiled regex that must match the module that is being warned | |
# - a line number for the line being warning, or 0 to mean any line | |
# If either if the compiled regexs are None, match anything. | |
_warnings_defaults = False | |
try: | |
from _warnings import (filters, default_action, once_registry, | |
warn, warn_explicit) | |
defaultaction = default_action | |
onceregistry = once_registry | |
_warnings_defaults = True | |
except ImportError: | |
filters = [] | |
defaultaction = "default" | |
onceregistry = {} | |
# Module initialization | |
_processoptions(sys.warnoptions) | |
if not _warnings_defaults: | |
silence = [ImportWarning, PendingDeprecationWarning] | |
# Don't silence DeprecationWarning if -3 or -Q was used. | |
if not sys.py3kwarning and not sys.flags.division_warning: | |
silence.append(DeprecationWarning) | |
for cls in silence: | |
simplefilter("ignore", category=cls) | |
bytes_warning = sys.flags.bytes_warning | |
if bytes_warning > 1: | |
bytes_action = "error" | |
elif bytes_warning: | |
bytes_action = "default" | |
else: | |
bytes_action = "ignore" | |
simplefilter(bytes_action, category=BytesWarning, append=1) | |
del _warnings_defaults |