pydoc > __future__

man perldoc info pydoc3 ri search

Help on module __future__:

📛 NAME

__future__ - Record of phased-in incompatible language changes.

🚀 Quick Reference

Use Case	Command	Description
Enable print function (Python 3 style)	from __future__ import print_function	Makes print a function instead of a statement
Enable true division	from __future__ import division	Changes / to return float division even with integers
Enable unicode literals	from __future__ import unicode_literals	Makes string literals unicode in Python 2
Enable absolute imports	from __future__ import absolute_import	Makes import behave like Python 3 (no implicit relative imports)
Enable generator stop	from __future__ import generator_stop	Makes StopIteration inside generators raise RuntimeError
Enable annotations	from __future__ import annotations	Makes function annotations lazy (PEP 563)
Enable nested scopes	from __future__ import nested_scopes	Enables lexical scoping of nested functions (PEP 227)
Enable generators	from __future__ import generators	Enables generator functions (PEP 255)
Enable with statement	from __future__ import with_statement	Enables context managers (PEP 343)
Barry’s FLUFL (optional)	from __future__ import barry_as_FLUFL	Changes != to <> (not recommended)

📚 MODULE REFERENCE

https://docs.python.org/3.10/library/__future__.html

The following documentation is automatically generated from the Python source files. It may be incomplete, incorrect or include features that are considered implementation detail and may vary between Python implementations. When in doubt, consult the module reference at the location listed above.

📖 DESCRIPTION

Each line is of the form:

FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease ","
                                  CompilerFlag ")"

where, normally, OptionalRelease < MandatoryRelease, and both are 5-tuples of the same form as sys.version_info:

(PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int
 PY_MINOR_VERSION, # the 1; an int
 PY_MICRO_VERSION, # the 0; an int
 PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string
 PY_RELEASE_SERIAL # the 3; an int
)

OptionalRelease records the first release in which

from __future__ import FeatureName

was accepted.

In the case of MandatoryReleases that have not yet occurred, MandatoryRelease predicts the release in which the feature will become part of the language.

Else MandatoryRelease records when the feature became part of the language; in releases at or after that, modules no longer need

from __future__ import FeatureName

to use the feature in question, but may continue to use such imports.

MandatoryRelease may also be None, meaning that a planned feature got dropped.

Instances of class _Feature have two corresponding methods, .getOptionalRelease() and .getMandatoryRelease().

CompilerFlag is the (bitfield) flag that should be passed in the fourth argument to the builtin function compile() to enable the feature in dynamically compiled code. This flag is stored in the .compiler_flag attribute on _Future instances. These values must match the appropriate #defines of CO_xxx flags in Include/cpython/compile.h.

No feature line is ever to be deleted from this file.

📊 DATA

• __all__ = ['all_feature_names', 'nested_scopes', 'generators', 'divisi...
• absolute_import = _Feature((2, 5, 0, 'alpha', 1), (3, 0, 0, 'alpha', 0...
• all_feature_names = ['nested_scopes', 'generators', 'division', 'absol...
• annotations = _Feature((3, 7, 0, 'beta', 1), (3, 11, 0, 'alpha', 0), 1...
• barry_as_FLUFL = _Feature((3, 1, 0, 'alpha', 2), (4, 0, 0, 'alpha', 0)...
• division = _Feature((2, 2, 0, 'alpha', 2), (3, 0, 0, 'alpha', 0), 1310...
• generator_stop = _Feature((3, 5, 0, 'beta', 1), (3, 7, 0, 'alpha', 0),...
• generators = _Feature((2, 2, 0, 'alpha', 1), (2, 3, 0, 'final', 0), 0)
• nested_scopes = _Feature((2, 1, 0, 'beta', 1), (2, 2, 0, 'alpha', 0), ...
• print_function = _Feature((2, 6, 0, 'alpha', 2), (3, 0, 0, 'alpha', 0)...
• unicode_literals = _Feature((2, 6, 0, 'alpha', 2), (3, 0, 0, 'alpha', ...
• with_statement = _Feature((2, 5, 0, 'alpha', 1), (2, 6, 0, 'alpha', 0)...

📁 FILE

/usr/lib/python3.10/__future__.py

📛 NAME 🚀 Quick Reference 📚 MODULE REFERENCE 📖 DESCRIPTION 📊 DATA 📁 FILE