Here is the example Python code:
def second():
print(x)
x += 1
print(x)
def first():
print(x)
second()
if __name__ == '__main__':
x = 'Test'
first()
print(x)
'x' is visible in the first function call, but not in the second. If 'x' is global, why can't it be seen in the second? If 'x' isn't global, how is it being seen in the first function call?