def _create_modulename(cdef_sources, source, sys_version):
 key = '\x00'.join([sys_version[:3], source, cdef_sources])
 key = key.encode('utf-8')
 k1 = hex((binascii.crc32(key[0::2]) & 4294967295))
 k1 = k1.lstrip('0x').rstrip('L')
 k2 = hex((binascii.crc32(key[1::2]) & 4294967295))
 k2 = k2.lstrip('0').rstrip('L')
 return '_Cryptography_cffi_{0}{1}'.format(k1, k2)

def _create_modulename ( cdef_sources , source , sys_version ) : key = '\x00' . join ( [ sys_version [ : 3 ] , source , cdef_sources ] ) key = key . encode ( 'utf-8' ) k1 = hex ( ( binascii . crc32 ( key [ 0 : : 2 ] ) & 4294967295 ) ) k1 = k1 . lstrip ( '0x' ) . rstrip ( 'L' ) k2 = hex ( ( binascii . crc32 ( key [ 1 : : 2 ] ) & 4294967295 ) ) k2 = k2 . lstrip ( '0' ) . rstrip ( 'L' ) return '_Cryptography_cffi_{0}{1}' . format ( k1 , k2 )
cffi creates a modulename internally that incorporates the cffi version .