装饰者的回报与实际回报不同

Question

Code

Why I am getting different results?

from time import time
def speed_test(func):
    def wrapper(*args, **kwargs):
        start = time()
        func(*args, **kwargs)
        end = time() - start
        print(f"Execution time is: {end:.17f}s  # Decorator")
    return wrapper
@speed_test 
def sorting(L):
    L.sort() # For example
    
def sorting_1(L1):
    L1.sort()
    
T = [10, 5, 3, 1, 0]
L = T.copy()

sorting(T)

a = time()
sorting_1(L)
b = time() - a
print(f"Execution time is: {b:.17f}s  # Main")

Expected output

Execution time is: 0.00000977516174316s  # Decorator
Execution time is: 0.00000977516174316s  # Main

My output

Execution time is: 0.00000977516174316s  # Decorator
Execution time is: 0.00000572204589844s  # Main

Why those two results are different? Edited: I mean this..

Answer 1

Two things I would say here:

1. time.perf_counter is more efficient for things like this
2. [A guess] In python, decorated functions "replace" the original function in the call stack, so they might be slower for that reason.