def encrypt(string, length): return ' '.join(string[i:i+length] for i in range(0,len(string),length))
encrypt('thisisarandomsentence',4) 给'this isar ando msen tenc e'

def encrypt(string, length): return ' '.join(string[i:i+length] for i in range(0,len(string),length))
encrypt('thisisarandomsentence',4) 给'this isar ando msen tenc e'