"""
This module adds several functions for interactive source code inspection.
"""


def get_class(lookup_view):
    """
    Convert a string version of a class name to the object.

    For example, get_class('sympy.core.Basic') will return
    class Basic located in module sympy.core
    """
    if isinstance(lookup_view, str):
        mod_name, func_name = get_mod_func(lookup_view)
        if func_name != '':
            lookup_view = getattr(
                __import__(mod_name, {}, {}, ['*']), func_name)
            if not callable(lookup_view):
                raise AttributeError(
                    "'%s.%s' is not a callable." % (mod_name, func_name))
    return lookup_view


def get_mod_func(callback):
    """
    splits the string path to a class into a string path to the module
    and the name of the class.

    Examples
    ========

    >>> from sympy.utilities.source import get_mod_func
    >>> get_mod_func('sympy.core.basic.Basic')
    ('sympy.core.basic', 'Basic')

    """
    dot = callback.rfind('.')
    if dot == -1:
        return callback, ''
    return callback[:dot], callback[dot + 1:]