根据我的机器，连接的速度（明显）更快。但是从风格上讲，如果性能不是很关键，我愿意付出替代的代价。好吧，如果我需要格式化，就不用问这个问题了……别无选择，只能使用插值/模板化。
>>> import timeit>>> def so_q_sub(n):... return "%s%s/%d" % (DOMAIN, QUESTIONS, n)...>>> so_q_sub(1000)'http://stackoverflow.com/questions/1000'>>> def so_q_cat(n):... return DOMAIN + QUESTIONS + '/' + str(n)...>>> so_q_cat(1000)'http://stackoverflow.com/questions/1000'>>> t1 = timeit.Timer('so_q_sub(1000)','from __main__ import so_q_sub')>>> t2 = timeit.Timer('so_q_cat(1000)','from __main__ import so_q_cat')>>> t1.timeit(number=10000000)12.166618871951641>>> t2.timeit(number=10000000)5.7813972166853773>>> t1.timeit(number=1)1.103492206766532e-05>>> t2.timeit(number=1)8.5206360154188587e-06>>> def so_q_tmp(n):... return "{d}{q}/{n}".format(d=DOMAIN,q=QUESTIONS,n=n)...>>> so_q_tmp(1000)'http://stackoverflow.com/questions/1000'>>> t3= timeit.Timer('so_q_tmp(1000)','from __main__ import so_q_tmp')>>> t3.timeit(number=10000000)14.564135316080637>>> def so_q_join(n):... return ''.join([DOMAIN,QUESTIONS,'/',str(n)])...>>> so_q_join(1000)'http://stackoverflow.com/questions/1000'>>> t4= timeit.Timer('so_q_join(1000)','from __main__ import so_q_join')>>> t4.timeit(number=10000000)9.4431309007150048
