diff options
| -rw-r--r-- | Doc/library/sys.rst | 23 |
1 files changed, 13 insertions, 10 deletions
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst index db5f374e76..55c06ca643 100644 --- a/Doc/library/sys.rst +++ b/Doc/library/sys.rst @@ -619,12 +619,13 @@ always available. .. data:: implementation - An object containing the information about the implementation of the - currently running Python interpreter. Its attributes are the those - that all Python implementations must implement. They are described - below. + An object containing information about the implementation of the + currently running Python interpreter. The following attributes are + required to exist in all Python implementations. - *name* is the implementation's identifier, like ``'cpython'``. + *name* is the implementation's identifier, e.g. ``'cpython'``. The actual + string is defined by the Python implementation, but it is guaranteed to be + lower case. *version* is a named tuple, in the same format as :data:`sys.version_info`. It represents the version of the Python @@ -633,7 +634,7 @@ always available. interpreter conforms, which ``sys.version_info`` represents. For example, for PyPy 1.8 ``sys.implementation.version`` might be ``sys.version_info(1, 8, 0, 'final', 0)``, whereas ``sys.version_info`` - would be ``sys.version_info(1, 8, 0, 'final', 0)``. For CPython they + would be ``sys.version_info(2, 7, 2, 'final', 0)``. For CPython they are the same value, since it is the reference implementation. *hexversion* is the implementation version in hexadecimal format, like @@ -646,10 +647,12 @@ always available. ``cache_tag`` is set to ``None``, it indicates that module caching should be disabled. - Regardless of its contents, :data:`sys.implementation` will not - change during a run of the interpreter, nor between implementation - versions. (It may change between Python language versions, - however.) See `PEP 421` for more information. + :data:`sys.implementation` may contain additional attributes specific to + the Python implementation. These non-standard attributes must start with + an underscore, and are not described here. Regardless of its contents, + :data:`sys.implementation` will not change during a run of the interpreter, + nor between implementation versions. (It may change between Python + language versions, however.) See `PEP 421` for more information. .. versionadded:: 3.3 |