Python: "global name 'time' is not defined"

Question

I'm writing a silly program in python for a friend that prints "We are the knights who say 'Ni'!". then sleeps for 3 seconds, and then prints "Ni!" twenty times at random intervals using the random module's uniform() method. Here's my code:

from time import sleep
import random

def knights_of_ni():
    generator = random.Random()
    print "We are the knights who say 'ni'."
    sleep(3)
    for i in range(0,20):
        print "Ni!"
        sleep(generator.uniform(0,2))

I've tried to import this module by typing in the interpreter from silly import knights_of_ni() and import silly, then calling the function with either knights_of_ni() or silly.knights_of_ni() (respectively), but I always get the same exception:

 NameError: global name 'time' is not defined

What is causing this error and how can I fix my code?

Edit: quite frankly, I'm not sure what problem I was having either. I ran the code the next morning and it worked just fine. I swear that the code produced errors last night... Anyway, thanks for your insight.

Answer 1

That's impossible. Your code example isn't the same as the code that produced that error.

Perhaps you had time.sleep(..) instead of sleep(..). You have done from time import sleep. To use the time.sleep(..) form you must import time

Answer 2

Apologies for the necropost but I ran into this problem too though in a slightly different way.

I was running time.time() with mod_python under Apache and Python . If I attempted to load the page with time.time() on it, it would fail complaining that "global name 'time' is not defined". However, if I ssh'd into my webserver and ran the exact same method from the command line, it would work.

In the end, restarting the Apache2 service fixed the issue. I'm not sure why this helped. I guess the module was unloaded at some point and then wouldn't reload, despite the import time command.

It's strange and a bit mysterious. Sorry I never hunted down the actual cause but hopefully this helps out the next person.

Answer 3

By importing the function into another file before calling it, you're only importing the contents of that function. The imports at the top of that file are not imported into your other file. You should put both of your imports into the function so that it looks like this:

def knights_of_ni():
    from time import sleep
    import random
    <the function contents>

This will verify that the imports that you want are available in the location that you call the function. There is no worry of double importing because python doesn't allow that - if time is imported in the file where this function is imported, it doesn't re