4.5. Introspection - The Python RTTI and Source information

4.5.1. Blueprint

The features provided by the package pysourceinfo are based on the standard package inspect with dynamic evaluation of additional sources where required. A flat call interface is provided for simplified application in OO as well as simple scripting.

The provided runtime structure information on Python sources is covered with basically one single type of interface

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 def getCaller<Interface>(spos=1):
    """ Stack position:
       spos==0 => caller(0==CallInterface)
       spos==1 => caller(1)
       spos==N => caller(N==level N)
    """
    pass

 def getModule<Interface>(spos=1):
    pass

 def getpythonpath<Interface>(spos=1):
    pass

The interface gathers the information on the defined ‘<Interface>’ from the call stack, loaded modules, or search path PATH/PYTHONPATH/sys.path.

The covered structural dynamic elements based on the call stack are:

  • package

  • module

  • function

  • class/method

  • name spaces - global/local

With additional functions covering mostly static information:

  • loaded module

  • sys.path - actual OID and load path

4.5.2. PySourceInfo - Information on Specific Object Categories

Although the standard package inspect provides a wide variety of information some are still not available. Therefore the missing is extracted by the combination of multiple sources and rules.

In general the main sources of information are given by the target type.

  • getCaller…

    This type works on the frame stack of inspect Some data, which is not directly provided, like the actual used PYTHONPATH item, are calculated by combination of multiple sources.

  • getModule…

    This type works on the module information mainly based on __file__, and __name__.

  • getpythonpath…

    This type correlates PYTHONPATH/sys.path with provided path and file names.

The objects for which the information could be requested are mainly categorized as follows.

  • function names and file pathnames

    Provided by inspect and the module object.

  • module names and file pathnames

    Provided by inspect and the module object.

  • package names and file pathnames

    Derived from the module information including the global name space, and the the current content of sys.path. Thus this could be unreliable under some circumstances.

4.5.3. Resources