1 """Python part of the warnings subsystem."""
3 # Note: function level imports should *not* be used
4 # in this module as it may cause import lock deadlock.
10 __all__
= ["warn", "showwarning", "formatwarning", "filterwarnings",
14 def warnpy3k(message
, category
=None, stacklevel
=1):
15 """Issue a deprecation warning for Python 3.x related changes.
17 Warnings are omitted unless Python is started with the -3 option.
21 category
= DeprecationWarning
22 warn(message
, category
, stacklevel
+1)
24 def _show_warning(message
, category
, filename
, lineno
, file=None, line
=None):
25 """Hook to write a warning to a file; replace if you like."""
29 file.write(formatwarning(message
, category
, filename
, lineno
, line
))
31 pass # the file (probably stderr) is invalid - this warning gets lost.
32 # Keep a worrking version around in case the deprecation of the old API is
34 showwarning
= _show_warning
36 def formatwarning(message
, category
, filename
, lineno
, line
=None):
37 """Function to format a warning the standard way."""
38 s
= "%s:%s: %s: %s\n" % (filename
, lineno
, category
.__name
__, message
)
39 line
= linecache
.getline(filename
, lineno
) if line
is None else line
45 def filterwarnings(action
, message
="", category
=Warning, module
="", lineno
=0,
47 """Insert an entry into the list of warnings filters (at the front).
49 Use assertions to check that all arguments have the right type."""
51 assert action
in ("error", "ignore", "always", "default", "module",
52 "once"), "invalid action: %r" % (action
,)
53 assert isinstance(message
, basestring
), "message must be a string"
54 assert isinstance(category
, (type, types
.ClassType
)), \
55 "category must be a class"
56 assert issubclass(category
, Warning), "category must be a Warning subclass"
57 assert isinstance(module
, basestring
), "module must be a string"
58 assert isinstance(lineno
, int) and lineno
>= 0, \
59 "lineno must be an int >= 0"
60 item
= (action
, re
.compile(message
, re
.I
), category
,
61 re
.compile(module
), lineno
)
65 filters
.insert(0, item
)
67 def simplefilter(action
, category
=Warning, lineno
=0, append
=0):
68 """Insert a simple entry into the list of warnings filters (at the front).
70 A simple filter matches all modules and messages.
72 assert action
in ("error", "ignore", "always", "default", "module",
73 "once"), "invalid action: %r" % (action
,)
74 assert isinstance(lineno
, int) and lineno
>= 0, \
75 "lineno must be an int >= 0"
76 item
= (action
, None, category
, None, lineno
)
80 filters
.insert(0, item
)
83 """Clear the list of warning filters, so that no filters are active."""
86 class _OptionError(Exception):
87 """Exception used by option processing helpers."""
90 # Helper to process -W options passed via sys.warnoptions
91 def _processoptions(args
):
95 except _OptionError
, msg
:
96 print >>sys
.stderr
, "Invalid -W option ignored:", msg
98 # Helper for _processoptions()
101 parts
= arg
.split(':')
103 raise _OptionError("too many fields (max 5): %r" % (arg
,))
104 while len(parts
) < 5:
106 action
, message
, category
, module
, lineno
= [s
.strip()
108 action
= _getaction(action
)
109 message
= re
.escape(message
)
110 category
= _getcategory(category
)
111 module
= re
.escape(module
)
113 module
= module
+ '$'
119 except (ValueError, OverflowError):
120 raise _OptionError("invalid lineno %r" % (lineno
,))
123 filterwarnings(action
, message
, category
, module
, lineno
)
125 # Helper for _setoption()
126 def _getaction(action
):
129 if action
== "all": return "always" # Alias
130 for a
in ('default', 'always', 'ignore', 'module', 'once', 'error'):
131 if a
.startswith(action
):
133 raise _OptionError("invalid action: %r" % (action
,))
135 # Helper for _setoption()
136 def _getcategory(category
):
140 if re
.match("^[a-zA-Z0-9_]+$", category
):
144 raise _OptionError("unknown warning category: %r" % (category
,))
146 i
= category
.rfind(".")
147 module
= category
[:i
]
148 klass
= category
[i
+1:]
150 m
= __import__(module
, None, None, [klass
])
152 raise _OptionError("invalid module name: %r" % (module
,))
154 cat
= getattr(m
, klass
)
155 except AttributeError:
156 raise _OptionError("unknown warning category: %r" % (category
,))
157 if not issubclass(cat
, Warning):
158 raise _OptionError("invalid warning category: %r" % (category
,))
162 # Code typically replaced by _warnings
163 def warn(message
, category
=None, stacklevel
=1):
164 """Issue a warning, or maybe ignore it or raise an exception."""
165 # Check if message is already a Warning object
166 if isinstance(message
, Warning):
167 category
= message
.__class
__
168 # Check category argument
170 category
= UserWarning
171 assert issubclass(category
, Warning)
172 # Get context information
174 caller
= sys
._getframe
(stacklevel
)
176 globals = sys
.__dict
__
179 globals = caller
.f_globals
180 lineno
= caller
.f_lineno
181 if '__name__' in globals:
182 module
= globals['__name__']
185 filename
= globals.get('__file__')
187 fnl
= filename
.lower()
188 if fnl
.endswith((".pyc", ".pyo")):
189 filename
= filename
[:-1]
191 if module
== "__main__":
193 filename
= sys
.argv
[0]
194 except AttributeError:
195 # embedded interpreters don't have sys.argv, see bug #839151
196 filename
= '__main__'
199 registry
= globals.setdefault("__warningregistry__", {})
200 warn_explicit(message
, category
, filename
, lineno
, module
, registry
,
203 def warn_explicit(message
, category
, filename
, lineno
,
204 module
=None, registry
=None, module_globals
=None):
206 module
= filename
or "<unknown>"
207 if module
[-3:].lower() == ".py":
208 module
= module
[:-3] # XXX What about leading pathname?
211 if isinstance(message
, Warning):
213 category
= message
.__class
__
216 message
= category(message
)
217 key
= (text
, category
, lineno
)
218 # Quick test for common case
219 if registry
.get(key
):
223 action
, msg
, cat
, mod
, ln
= item
224 if ((msg
is None or msg
.match(text
)) and
225 issubclass(category
, cat
) and
226 (mod
is None or mod
.match(module
)) and
227 (ln
== 0 or lineno
== ln
)):
230 action
= defaultaction
232 if action
== "ignore":
236 # Prime the linecache for formatting, in case the
237 # "file" is actually in a zipfile or something.
238 linecache
.getlines(filename
, module_globals
)
240 if action
== "error":
245 oncekey
= (text
, category
)
246 if onceregistry
.get(oncekey
):
248 onceregistry
[oncekey
] = 1
249 elif action
== "always":
251 elif action
== "module":
253 altkey
= (text
, category
, 0)
254 if registry
.get(altkey
):
257 elif action
== "default":
260 # Unrecognized actions are errors
262 "Unrecognized action (%r) in warnings.filters:\n %s" %
264 # Warn if showwarning() does not support the 'line' argument.
265 # Don't use 'inspect' as it relies on an extension module, which break the
266 # build thanks to 'warnings' being imported by setup.py.
268 if hasattr(showwarning
, 'func_code'):
269 fxn_code
= showwarning
.func_code
270 elif hasattr(showwarning
, '__func__'):
271 fxn_code
= showwarning
.__func
__.func_code
273 args
= fxn_code
.co_varnames
[:fxn_code
.co_argcount
]
274 if 'line' not in args
:
275 showwarning_msg
= ("functions overriding warnings.showwarning() "
276 "must support the 'line' argument")
277 if message
== showwarning_msg
:
278 _show_warning(message
, category
, filename
, lineno
)
280 warn(showwarning_msg
, DeprecationWarning)
281 # Print message and context
282 showwarning(message
, category
, filename
, lineno
)
285 # filters contains a sequence of filter 5-tuples
286 # The components of the 5-tuple are:
287 # - an action: error, ignore, always, default, module, or once
288 # - a compiled regex that must match the warning message
289 # - a class representing the warning category
290 # - a compiled regex that must match the module that is being warned
291 # - a line number for the line being warning, or 0 to mean any line
292 # If either if the compiled regexs are None, match anything.
293 _warnings_defaults
= False
295 from _warnings
import (filters
, default_action
, once_registry
,
297 defaultaction
= default_action
298 onceregistry
= once_registry
299 _warnings_defaults
= True
302 defaultaction
= "default"
306 # Module initialization
307 _processoptions(sys
.warnoptions
)
308 if not _warnings_defaults
:
309 simplefilter("ignore", category
=PendingDeprecationWarning
, append
=1)
310 simplefilter("ignore", category
=ImportWarning
, append
=1)
311 bytes_warning
= sys
.flags
.bytes_warning
312 if bytes_warning
> 1:
313 bytes_action
= "error"
315 bytes_action
= "default"
317 bytes_action
= "ignore"
318 simplefilter(bytes_action
, category
=BytesWarning
, append
=1)
319 del _warnings_defaults