Python Pocket Reference, 3rd Edition

Built-in Attributes

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the warnings framework to issue warnings by calling the

warnings.warn function:

warnings.warn("feature X no longer supported")

In addition, you can add filters to disable certain warnings.

You can apply a regular expression pattern to a message or

module name to suppress warnings with varying degrees of

generality. For example, you can suppress a warning about

the use of the deprecated

regex module by calling:

import warnings

warnings.filterwarnings(action = 'ignore',

message='.*regex module*',

category=DeprecationWarning,

module = '__main__')

This adds a filter that affects only warnings of the class

DeprecationWarning triggered in the __main__ module,

applies a regular expression to match only the message that

names the

regex module being deprecated, and causes such

warnings to be ignored. Warnings can be printed only once,

printed every time the offending code is executed, or turned

into exceptions that will cause the program to stop (unless

the exceptions are caught). See the

warnings module docu-

mentation in Version 2.1 and later for more information. See

also the

-W argument in the section “Command-Line

Options,” earlier in this book.

Built-in Attributes

Some objects export special attributes that are predefined by

Python.

*

The following is a partial list because many types

have unique attributes all their own; see the entries for spe-

cific types in the Python Library Reference. ...