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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def resolve(str_or_obj):
 """Returns object from string"""

    from rope.base.utils.pycompat import string_types
    if not isinstance(str_or_obj, string_types):
        return str_or_obj
    if '.' not in str_or_obj:
        str_or_obj += '.'
    mod_name, obj_name = str_or_obj.rsplit('.', 1)
    __import__(mod_name)
    mod = sys.modules[mod_name]
    return getattr(mod, obj_name) if obj_name else mod