Multivariate Pattern Analysis in Python

# mvpa2.base.externals.exists

`mvpa2.base.externals.``exists`(dep, force=False, raise_=False, issueWarning=None, exception=<type 'exceptions.RuntimeError'>)

  Test whether a known dependency is installed on the system.

  This method allows us to test for individual dependencies without testing all known dependencies. It also ensures that we only test for a dependency once.

  Parameters:

  dep : string or list of string

  > The dependency key(s) to test.

  force : boolean

  > Whether to force the test even if it has already been performed.

  raise_ : boolean, str

  > Whether to raise an exception if dependency is missing. If True, it is still conditioned on the global setting MVPA_EXTERNALS_RAISE_EXCEPTION, while would raise exception if missing despite the configuration if ‘always’.

  issueWarning : string or None or True

  > If string, warning with given message would be thrown. If True, standard message would be used for the warning text.

  exception : exception, optional

  > What exception to raise. Defaults to RuntimeError