This module essentially performs introspection on the Python interpreter itself, to discover which language features are available.

Usage notes:

The recommended way to use this module is:

Using the 'pyconfig' object like this auto-caches results so you can use the function calls inline without a speed penalty of rerunning the test each time.

Background/rationale:

At first glance, this module seems odd — why not just check sys.version_info? Well, for example:

• You could be running under a nonstandard/alternative Python implementation (e.g. Jython, or maybe a cut-down embedded version that eliminated some features) and you want to dynamically figure out what is available.
  
  

• It seems more self-documenting to write something like:
      
  if Have_Iterators():
       ... do something with iterators ...
  Than to write:
      
  if sys.version_info[0] >= 2 and sys.version_info[1] >= 2:
       ... do something with iterators ...
  In other words, your code now says "here is the capability I need", making it more maintainable down the road than a hardcoded version match. Plus, it is more robust in the presence of a nonstandard interpreter.
  
  

• You're writing an installer, and want to pick different modules to install, based on platform.
  
  

• Some oddball (or future) version of Python might break sys.version_info (expand the number of values, etc.), so you don't want to rely on it.
  
  
  blog comments powered by Disqus