python不能画图，是咋回事？

>>> import turtle as t
Traceback (most recent call last):
  File "<pyshell#3>", line 1, in <module>
    import turtle as t
  File "E:\zwg\pythonst\turtle.py", line 20, in <module>
    move(0, 100)
  File "E:\zwg\pythonst\turtle.py", line 6, in move
    turtle.penup()
AttributeError: 'module' object has no attribute 'penup'