code: def _calcsize(fmt):
      '''struct.calcsize() handling 'z' for Py_ssize_t.
      '''
       # sizeof(long) != sizeof(ssize_t) on LLP64
      if _sizeof_Clong < _sizeof_Cvoidp: # pragma: no coverage
          z = 'P'
      else:
          z = 'L'
      return calcsize(fmt.replace('z', z)f _calcsize(fmt):
      '''struct.calcsize() handling 'z' for Py_ssize_t.
      '''
       # sizeof(long) != sizeof(ssize_t) on LLP64
      if _sizeof_Clong < _sizeof_Cvoidp: # pragma: no coverage
          z = 'P'
      else:
          z = 'L'
      return calcsize(fmt.replace('z', z))
docs: struct.calcsize() handling 'z' for Py_ssize_t.