side_effect_code.py

# Bad
name = "Cristiano Rolando"
def split_into_first_and_last_name():
  global name
  name = name.split()

# ketika fungsi dieksusi akan merusak dari global variabel name
split_into_first_and_last_name()
print(name)

# Good
def split_into_first_and_last_name(name):
  return name.split()

name = "Cristiano Rolando"
# ketika fungi dieksekusi tidak akan merusak variabel name awal, karena di passing dengan argumen
first_name, last_name = split_into_first_and_last_name(name)
print(first_name, last_name)