random.seed AttributeError: module 'random' has no attribute 'randrange'

I found errors to this script. I have no idea why, because the standard module / lib supposed to be exist by default. This is the snippet.

#!/usr/bin/python -u
import random
import string

flag = "FLAG:"+("fffaa\n")[:-1]
enkripflag = ""
random.seed("random")
for c in flag:
    if c.islower():
        enkripflag += chr((ord(c)-ord('a')+random.randrange(0,26))%26 + ord('a'))ord('a'))

full : https://gist.github.com/0x4164/797ead20f512241723ea66a3a8fcbafa

The error occured when executing random.seed() & random.randrange()

stacktrace :

Traceback (most recent call last):
  File "random.py", line 2, in <module>
    import random
  File "/media/data3/play/pucc/random.py", line 10, in <module>
    random.seed(1)
AttributeError: 'module' object has no attribute 'seed'