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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 from_python_src( cls, pySrc, lambdas_path, json_filename: str, stem: str, save_file: bool = False, ):
 """Builds GrFN object from Python source code."""

        asts = [ast.parse(pySrc)]
        pgm_dict = genPGM.create_pgm_dict(
            lambdas_path,
            asts,
            json_filename,
            {"FileName": f"{stem}.py"},  # HACK
        )
        lambdas = importlib.__import__(stem + "_lambdas")
        return cls.from_dict(pgm_dict, lambdas)