Local (?) variable referenced before assignment [duplicate]

test1 = 0
def testFunc():
    test1 += 1
testFunc()

I am receiving the following error:

UnboundLocalError: local variable 'test1' referenced before assignment.

Error says that 'test1' is local variable but i thought that this variable is global

So is it global or local and how to solve this error without passing global test1 as argument to testFunc?

Solution 1:

In order for you to modify test1 while inside a function you will need to do define test1 as a global variable, for example:

test1 = 0
def testFunc():
    global test1 
    test1 += 1
testFunc()

However, if you only need to read the global variable you can print it without using the keyword global, like so:

test1 = 0
def testFunc():
     print test1 
testFunc()

But whenever you need to modify a global variable you must use the keyword global.

Solution 2:

Best solution: Don't use globals

>>> test1 = 0
>>> def test_func(x):
        return x + 1

>>> test1 = test_func(test1)
>>> test1
1

Solution 3:

You have to specify that test1 is global:

test1 = 0
def testFunc():
    global test1
    test1 += 1
testFunc()