human
I am working on the file ".ipynb_checkpoints/python-tutorial-checkpoint.ipynb".
The first task is:
Functions
Python functions are defined using the def keyword. For example:
Can you write Python code for it?

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Write me a the Python code you requested?
assistant
#Here is the Python code you requested.

def sign(x):
    if x > 0:
        return 'positive'
    elif x < 0:
        return 'negative'
    else:
        return 'zero'

for x in [-1, 0, 1]:
    print (sign(x))