comment échanger les nombres en python mathématiquement

def swap_by_temp_var(num1,num2):
    temp = num1
    num1 = num2
    num2 = temp
    return num1, num2
def swap_by_mathamatically(num1,num2):
    num1 = num1 + num2
    num2 = num1-num2
    num1 = num1-num2
    return num1, num2
print(swap_by_temp_var(100,80))
print(swap_by_mathamatically(100,80))
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