Correct Use Of Global Variables In Python 3

Question

Which is the correct use of global variables in Python 3?:

1) Stating global VAR_NAME once in the core script (not within a function) and then simply re

Answer 1

"in a way that would otherwise be interpreted as an assignment to a local variable" --- yes, but here is a subtle detail:

------------------- error: local variable 'c' referenced before assignment

def work():
  c += 3

c = 0

work()
print(c)

------------------- error: local variable 'c' referenced before assignment

c = 0

def work():
  c += 3

work()
print(c)

------------------- prints [3]

def work():
  c.append(3)

c = []

work()
print(c)

------------------- prints [3]

c = []

def work():
  c.append(3)

work()
print(c)