为什么python不会引发NameError

Question

Consider this simple case:

i = 10
if i != id:
    print i

As id is not defined here so i was assuming to get NameError: name 'id' is not defined but it does not raise any.

But in this case:

id = 10
if i != id:
    print i

It actually raised a NameError exception for i . So can anyone explain it to me this behaviour?

Answer 1

id is a built-in function, so it actually is defined. Use another name for your variable.

Here is a list of all built-in functions .