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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 create_pgm_dict( lambdaFile: str, asts: List, file_name: str, mode_mapper_dict: dict, save_file=False, ) -> Dict: """ Create a Python dict representing the PGM, with additional metadata for JSON output. """


    lambdaStrings = ["import math\n\n"]
    state = PGMState(lambdaStrings)
    generator = GrFNGenerator()
    generator.mode_mapper = mode_mapper_dict
    pgm = generator.genPgm(asts, state, {}, "")[0]
    if pgm.get("start"):
        pgm["start"] = pgm["start"][0]
    else:
        pgm["start"] = generator.function_defs[-1]

    pgm["source"] = [[get_path(file_name, "source")]]

    # dateCreated stores the date and time on which the lambda and PGM file was created.
    # It is stored in YYYMMDD format
    pgm["dateCreated"] = f"{datetime.today().strftime('%Y%m%d')}"

    with open(lambdaFile, "w") as f:
        f.write("".join(lambdaStrings))

    # View the PGM file that will be used to build a scope tree
    if save_file:
        json.dump(pgm, open(file_name[:file_name.rfind(".")] + ".json", "w"))

    return pgm