parameters: (self, requirement, installer=None)
docstring: Obtain a distribution matching `requirement` (e.g. via download)
  
          Obtain a distro that matches requirement (e.g. via download).  In the
          base ``Environment`` class, this routine just returns
          ``installer(requirement)``, unless `installer` is None, in which case
          None is returned instead.  This method is a hook that allows subclasses
          to attempt other ways of obtaining a distribution before falling back
          to the `installer` argument.
docstring_summary: Obtain a distribution matching `requirement` (e.g. via download)
docstring_tokens: Obtain a distribution matching requirement ( e . g . via download )
function: def obtain(self, requirement, installer=None):
          """Obtain a distribution matching `requirement` (e.g. via download)
  
          Obtain a distro that matches requirement (e.g. via download).  In the
          base ``Environment`` class, this routine just returns
          ``installer(requirement)``, unless `installer` is None, in which case
          None is returned instead.  This method is a hook that allows subclasses
          to attempt other ways of obtaining a distribution before falling back
          to the `installer` argument."""
          if installer is not None:
              return installer(requirement)
function_tokens: def obtain ( self , requirement , installer = None ) : if installer is not None : return installer ( requirement )