python 遍历 两列表比较A列表中是否存在于B列表的两种方法的 性能测试

在遍历对比中，我曾使用.index函数去对列表元素进行比较，在index函数中，描述为

检测字符串中是否包含子字符串 str

这意味着A元素并不是完全等同于B元素，而是B元素中包含了A元素，在这种情况下，才需要使用到index函数，盲目使用函数或许浪费大部分性能，并且index抛出错误，使用try将再次损耗性能

所以 我做了以下测试，去验证性能

首先使用time模块并定义两个列表用于比较

import time

list=[1,2,3,4,5,6,7]

list1=[1,2,3,4,5,6,7,8,9,10,11,12,13,14]

由于单独运行的结果非常小，所以采用同样的循环增加次数

k=0

while k < 10000:

    k+=1

完整验证代码如下

#列表查找检测
import time
list=[1,2,3,4,5,6,7]
list1=[1,2,3,4,5,6,7,8,9,10,11,12,13,14]

start = time.time()

k=0
while k < 10000:
    k+=1
    for i in list1:
        for n in list:
            if i == n :
                object_listnnnn = i
            else:
                object_listnnnn = i



end = time.time()
print((end - start))
start = time.time()

k=0
while k < 10000:
    k+=1
    for i in list1:
        for n in list:
            try:
                object_listnnnn = list.index(i)
                object_listnnnn = i

            except:
                object_listnnnn = i


end = time.time()
print((end - start))

测试数据如下

1.06718468666077	0.982396841049194	0.918120622634888	0.963332414627075	0.993014097213745	0.984809732437134
0.36103343963623	0.38300609588623	0.279305219650269	0.346380472183228	0.378976345062256	0.349740314483643
2.91480660438538	2.90445351600647	2.81602907180786	2.87438821792603	2.87952947616577	2.8778413772583

明显采用第一种方法速度将是大于一倍

==========修改

在代码段

k=0
while k < 10000:
    k+=1
    for i in list1:
        for n in list:
            try:
                object_listnnnn = list.index(i)
                object_listnnnn = i

            except:
                object_listnnnn = i

中，list.index无需遍历list，将list改为n此遍历才起作用，所以将代码更改如下

tps=0
while tps <5 :
    tps +=1
    #列表查找检测


    import time
    list=[1,2,3,4,5,6,7]
    list1=[1,2,3,4,5,6,7,8,9,10,11,12,13,14]

    start = time.time()

    k=0
    while k < 10000:
        k+=1
        for i in list1:
            for n in list:
                if i == n :
                    object_listnnnn = i
                else:
                    object_listnnnn = i



    end = time.time()
    print((end - start))
    start = time.time()

    k=0
    while k < 10000:
        k+=1
        for i in list1:
            try:
                object_listnnnn = list.index(i)
                object_listnnnn = i
            except:
                object_listnnnn = i



    end = time.time()
    print((end - start))
    start = time.time()



    k=0
    while k < 10000:
        k+=1
        for i in list1:
            for n in list:
                try:
                    object_listnnnn = n.index(i)
                    object_listnnnn = i

                except:
                    object_listnnnn = i

    end = time.time()
    print((end - start))

性能测试如下

平均

0.984809732437134

0.349740314483643

2.8778413772583