爲％s的速度比+爲Python的字符串連接

Question

瞭解，使用str.join運營商是「選擇」的方式來連接在Python中，我徘徊在那裏的類型啄食順序操作：

"%s %s" % (first_name, last_name) 

會適合。它們比使用+更快還是更慢？

Answer 1

讓我們來看看：

>>> first_name = 'Test' 
>>> last_name = 'Name' 

>>> %timeit "%s %s" % (first_name, last_name) 
10000000 loops, best of 3: 168 ns per loop 

>>> %timeit ' '.join((first_name, last_name)) 
10000000 loops, best of 3: 157 ns per loop 

>>> %timeit first_name + ' ' + last_name 
10000000 loops, best of 3: 103 ns per loop 

如果您緩存的元組：

>>> name_tuple = (first_name, last_name) 

>>> %timeit "%s %s" % name_tuple 
10000000 loops, best of 3: 125 ns per loop 

>>> %timeit ' '.join(name_tuple) 
10000000 loops, best of 3: 114 ns per loop 

Answer 2

答：不可以

In [1]: tup = 'hello', 'world' 

In [2]: timeit 'hello' + 'world' 
10000000 loops, best of 3: 20.2 ns per loop 

In [3]: timeit tup[0] + tup[1] 
10000000 loops, best of 3: 129 ns per loop 

In [4]: timeit '{}{}'.format('hello', 'world') 
1000000 loops, best of 3: 285 ns per loop 

In [5]: timeit '{}{}'.format(*tup) 
1000000 loops, best of 3: 281 ns per loop 

In [6]: timeit '%s%s' % ('hello', 'world') 
10000000 loops, best of 3: 122 ns per loop 

In [7]: timeit '%s%s' % tup 
10000000 loops, best of 3: 135 ns per loop 

In [8]: timeit ''.join(['hello', 'world']) 
1000000 loops, best of 3: 210 ns per loop 

In [9]: timeit ''.join(tup) 
10000000 loops, best of 3: 121 ns per loop