这只是为了外观。您可以一眼看出格式是什么。我们中的许多人都比微优化更喜欢可读性。
让我们看看IPython的意思
%timeit：
Python 3.7.2 (default, Jan 3 2019, 02:55:40)IPython 5.8.0Intel(R) Core(TM) i5-4590T CPU @ 2.00GHzIn [1]: %timeit root = "sample"; output = "output"; path = "{}/{}".format(root, output)The slowest run took 12.44 times longer than the fastest. This could mean that an intermediate result is being cached.1000000 loops, best of 5: 223 ns per loopIn [2]: %timeit root = "sample"; output = "output"; path = root + '/' + outputThe slowest run took 13.82 times longer than the fastest. This could mean that an intermediate result is being cached.10000000 loops, best of 5: 101 ns per loopIn [3]: %timeit root = "sample"; output = "output"; path = "%s/%s" % (root, output)The slowest run took 27.97 times longer than the fastest. This could mean that an intermediate result is being cached.10000000 loops, best of 5: 155 ns per loopIn [4]: %timeit root = "sample"; output = "output"; path = f"{root}/{output}"The slowest run took 19.52 times longer than the fastest. This could mean that an intermediate result is being cached.10000000 loops, best of 5: 77.8 ns per loop
