code: def human2bytes(s):
      
      symbols = ('B', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y')
      letter = s[-1:].strip().upper()
      num = s[:-1]
      assert num.isdigit() and letter in symbols, s
      num = float(num)
      prefix = {symbols[0]: 1}
      for i, s in enumerate(symbols[1:]):
          prefix[s] = 1 << (i + 1) * 10
      return int(num * prefix[letter])
docs: >>> human2bytes('1M')
      1048576
      >>> human2bytes('1G')
      1073741824