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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 main():
 """ NAME grab_magic_key.py DESCRIPTION picks out key and saves to file SYNTAX grab_magic_key.py [command line optins] OPTIONS -h prints help message and quits -f FILE: specify input magic format file -key KEY: specify key to print to standard output """

    dir_path = "./"
    if '-WD' in sys.argv:
        ind = sys.argv.index('-WD')
        dir_path = sys.argv[ind+1]
    if '-h' in sys.argv:
        print(main.__doc__)
        sys.exit()
    if '-f' in sys.argv:
        ind = sys.argv.index('-f')
        magic_file = dir_path+'/'+sys.argv[ind+1]
    else:
        print(main.__doc__)
        sys.exit()
    if '-key' in sys.argv:
        ind = sys.argv.index('-key')
        grab_key = sys.argv[ind+1]
    else:
        print(main.__doc__)
        sys.exit()
    #
    #
    # get data read in
    Data, file_type = pmag.magic_read(magic_file)
    if len(Data) > 0:
        for rec in Data:
            print(rec[grab_key])
    else:
        print('bad file name')