python列出一个文件

Question

该脚本实际上不适用于所需的输入

脚本：

import csv
file1 = csv.reader(open("1.csv"))
file2 = csv.reader(open("2.csv"))
file3 = open("3.csv", "w")
k, l = list(file1),list(file2)
length_file1 = len(k)
length_file2 = len(l)
n = []
file3.write(",".join(str(i) for i in l[0])+'\n')
for i in xrange(1, length_file1):
    arr = k[i][1]
    for j in xrange(1, length_file2):
        arr2 = l[j][1]
        if arr == arr2:
            l[j][0] = k[i][0]
            print l[j]
            n.append(l[j])
            file3.write(",".join(str(i) for i in l[j])+'\n')

所以我想替换代码

Answer 1

您可以创建一个键的字典：从值对1.csv和使用比较每个值2.csv从字典中的项。 这是使用Python3，这里不需要使用range和xrange ，可以直接遍历列表。

import csv

with open("2.csv", 'r') as f:
    file2 = csv.reader(f)
    file2 = [j for _,j in file2] # This is to remove the blank item at the start of each row

with open("1.csv", 'r') as f:
    file1 = csv.reader(f)
    file1 = {i:j for j,i in file1}

    toWrite = []

    for i in file2:
        if i in file1.keys():
            toWrite.append("{},{}".format(file1[i],i))

with open("bdsp_updated.csv", "w") as f:
    f.write('\n'.join(toWrite))

bdsp_updated.csv内容：

1,99277050
10,92782013
2,71269815
3,99724582
7,92043333
4,92011116
8,99799635