__future__ Namespace Reference

Data Structures
class	_Feature

Variables
list	all_feature_names
list	__all__ = ["all_feature_names"]
int	CO_NESTED = 0x0010
int	CO_GENERATOR_ALLOWED = 0x1000
int	CO_FUTURE_DIVISION = 0x2000
tuple	nested_scopes
tuple	generators
tuple	division

Detailed Description

Record of phased-in incompatible language changes.

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/compile.h.

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

Variable Documentation

list __all__ = ["all_feature_names"]

Definition at line 56 of file __future__.py.

list all_feature_names

Initial value:

= [
    "nested_scopes",
    "generators",
    "division",
]

Definition at line 50 of file __future__.py.

int CO_FUTURE_DIVISION = 0x2000

Definition at line 64 of file __future__.py.

int CO_GENERATOR_ALLOWED = 0x1000

Definition at line 63 of file __future__.py.

int CO_NESTED = 0x0010

Definition at line 62 of file __future__.py.

tuple division

Initial value:

= _Feature((2, 2, 0, "alpha", 2),
                    (3, 0, 0, "alpha", 0),
                    CO_FUTURE_DIVISION)

Definition at line 102 of file __future__.py.

tuple generators

Initial value:

= _Feature((2, 2, 0, "alpha", 1),
                      (2, 3, 0, "final", 0),
                      CO_GENERATOR_ALLOWED)

Definition at line 98 of file __future__.py.

tuple nested_scopes

Initial value:

= _Feature((2, 1, 0, "beta",  1),
                         (2, 2, 0, "alpha", 0),
                         CO_NESTED)

Definition at line 94 of file __future__.py.