如何将2个CSV文件与公共列值组合，但两个文件具有不同的行数 [英] How to combine 2 csv files with common column value, but both files have different number of lines

问题描述

file1.csv contains 2 columns: c11;c12
file2.csv contains 2 columns: c21;c22
Common column: c11, c21

示例：

f1.csv

a;text_a            
b;text_b            
f;text_f            
x;text_x

f2.csv

a;path_a
c;path_c
d;path_d
k;path_k
l;path_l
m:path_m

输出f1 + f2：

a;text_a;path_a
b;text_b,''
c;'';path_c
d;'';path_d
f;text_f;''
k;'';path_k
l;'';path_l
m;'';path_m
x;text_x;''

如何使用python实现？

How to realize it using python?

推荐答案

这是很容易使用csv模块：

This is quite easily done with the csv module:

import csv

with open('file1.csv') as f:
    r = csv.reader(f, delimiter=';')
    dict1 = {row[0]: row[1] for row in r}

with open('file2.csv') as f:
    r = csv.reader(f, delimiter=';')
    dict2 = {row[0]: row[1] for row in r}

keys = set(dict1.keys() + dict2.keys())
with open('output.csv', 'wb') as f:
    w = csv.writer(f, delimiter=';')
    w.writerows([[key, dict1.get(key, "''"), dict2.get(key, "''")]
                 for key in keys])

这篇关于如何将2个CSV文件与公共列值组合，但两个文件具有不同的行数的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！