Revised, simplified version of https://stackoverflow.com/a/2612990/4518341

my_results

copy.copy: 0.03886294364929199
copy.deepcopy: 2.6126625537872314
list slicing [:]: 0.017081499099731445
list(L): 0.01966571807861328
list comprehension: 0.04840683937072754
list extend: 0.020438432693481445
list append: 0.10321950912475586
generator expression extend: 0.08307862281799316

tmp.py

#!/usr/bin/env python3.10

class new_class:
    def __init__(self):
        self.blah = 'blah'

if __name__ == '__main__':
    import copy
    from time import time

    num_times = 10_0000
    L = [None, 'blah', 1, 543.4532,
         ['foo'], ('bar',), {'blah': 'blah'},
         new_class()]

    t = time()
    for _ in range(num_times):
        copy.copy(L)
    print('copy.copy:', time()-t)

    t = time()
    for _ in range(num_times):
        copy.deepcopy(L)
    print('copy.deepcopy:', time()-t)

    t = time()
    for _ in range(num_times):
        L[:]
    print('list slicing [:]:', time()-t)

    t = time()
    for _ in range(num_times):
        list(L)
    print('list(L):', time()-t)

    t = time()
    for _ in range(num_times):
        [i for i in L]
    print('list comprehension:', time()-t)

    t = time()
    for _ in range(num_times):
        a = []
        a.extend(L)
    print('list extend:', time()-t)

    t = time()
    for _ in range(num_times):
        a = []
        for y in L:
            a.append(y)
    print('list append:', time()-t)

    t = time()
    for _ in range(num_times):
        a = []
        a.extend(i for i in L)
    print('generator expression extend:', time()-t)