code: def unhex(s):
      """Get the integer value of a hexadecimal number."""
      bits = 0
      for c in s:
          c = bytes((c,))
          if b"0" <= c <= b"9":
              i = ord("0")
          elif b"a" <= c <= b"f":
              i = ord("a") - 10
          elif b"A" <= c <= b"F":
              i = ord(b"A") - 10
          else:
              assert False, "non-hex digit " + repr(c)
          bits = bits * 16 + (ord(c) - i)
      return bits
  
file_path: cpython/Lib/quopri.py
label_desc: Use image node_id 8 for calling a global function with example usage: unhex(s) and returns: bits