Pass by Ref Test
def add_to_list(list):
list.append('three')list = ['one', 'two']add_to_list(list)print(list)['one', 'two', 'three']
Key takeaway:
1- You can use the reference that a function receives as its arguments, to modify the ‘outside’ value of a variable, as long as you don’t reassign the parameter to refer to a new object.
2- Assigning to an immutable type will always create a new object, which breaks the reference that you had to the outside variable.
https://stackoverflow.com/questions/986006/how-do-i-pass-a-variable-by-reference