python字符串连接的方法,一般有以下三种:

方法1:直接通过加号(+)操作符连接website=& 39;python& 39;+& 39;tab& 39;+& 39; com& 39;

方法2:python字符串连接的方法,一般有以下三种:

  • 1:直接通过加号(+)操作符连接
website = 'python' + 'baidu' + '.com'
  • 2:join方法
listStr = ['python', 'baidu', '.com'] 
website = ''.join(listStr)
  • 3:替换
website = '%s%s%s' % ('python', 'baidu', '.com')

下面再来说一下三种方法的不同

  • 方法1,使用简单直接,但是网上不少人说这种方法效率低
    之所以说python 中使用 + 进行字符串连接的操作效率低下,是因为python中字符串是不可变的类型,使用 + 连接两个字符串时会生成一个新的字符串,生成新的字符串就需要重新申请内存,当连续相加的字符串很多时(a+b+c+d+e+f+…) ,效率低下就是必然的了
  • 方法2,使用略复杂,但对多个字符进行连接时效率高,只会有一次内存的申请。而且如果是对list的字符进行连接的时候,这种方法必须是首选
  • 方法3:字符串格式化,这种方法非常常用,本人也推荐使用该方法

下面用实验来说明字符串连接的效率问题。

案例一:

from time import time
def method1():
    t = time()
    for i in range(100000):
        s = 'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'+'python'
    print (time() - t)
def method2():
    t = time()
    for i in range(100000):
        s = ''.join(['python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python','python'])
    print (time() -t)
method1()
method2()

结果:

0.0029921531677246094
0.09973287582397461