Python's function scope

Question

I am working with python and doing the following.

x = [1,2,3,4,5]

def function1():
  print(x)

function1()

I would think that I would get the error name 'x' is not defined but I do not, it prints the variable x even though it is not defined in the function. Why does python let me use variables that are defined outside of a function inside a function even though they have different scopes?

read my answer here > http://stackoverflow.com/questions/26067976/basic-python-function-and-outputs/26068060#26068060 — Mazdak, Oct 03 '14 at 21:50

score 0 · Answer 1 · answered Oct 03 '14 at 21:47

0

Basically you are setting x to a global variable.

x = "myString"

function global():
    print(x) // Global


function notglobal():
    y = "myOtherString"
    print(y) // Not Global

class myClass: 
    z = "notGlobal" // Not Global

    function printZ():
        print(z) // Global To class

print(z) // Not global so will error out

answered Oct 03 '14 at 21:47

Bioto

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how do choose a variable to be global or not? – biw Oct 03 '14 at 21:48
If its outside a class/function its global – Bioto Oct 03 '14 at 21:48
can you edit you answer to explain a little better? – biw Oct 03 '14 at 21:49
There ya go. Should be updated i hope it explains – Bioto Oct 03 '14 at 21:52

score 0 · Answer 2 · answered Oct 03 '14 at 21:50

0

x is global, which means all functions can use it.

answered Oct 03 '14 at 21:50

Thedudxo

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score 0 · Answer 3 · answered Oct 03 '14 at 21:51

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I like the treatment offered by this blog post, which compares the described behaviour to Javascript's variable hoisting (although the blog uses the negative example to demonstrate it).

answered Oct 03 '14 at 21:51

TML

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Python's function scope

3 Answers3