Question

我有两个.csv文件，我需要加入一个新文件或将一个文件追加到另一个文件中：

filea中：

jan,feb,mar
80,50,52
74,73,56

FILEB：

apr,may,jun
64,75,64
75,63,63

我需要的是：

jan,feb,mar,apr,may,jun
80,50,52,64,75,64
74,73,56,75,63,63

我得到了什么：

jan,feb,mar
80,50,52
74,73,56
apr,may,jun
64,75,64
75,63,63

我使用我能找到的最简单的代码。我想有点太简单了：

sourceFile = open('fileb.csv', 'r')
data = sourceFile.read()
with open('filea.csv', 'a') as destFile:
    destFile.write(data

如果有人能告诉我自己做错了什么以及如何让他们水平追加，我将非常感激。而不是＆＃39;垂直＆＃39;。

Answer 1

from itertools import izip_longest
with open("filea.csv") as source1,open("fileb.csv")as source2,open("filec.csv","a") as dest2:
    zipped = izip_longest(source1,source2) # use izip_longest which will add None as a fillvalue where we have uneven length files
    for line in zipped:
        if line[1]: # if we have two lines to join
            dest2.write("{},{}\n".format(line[0][:-1],line[1][:-1]))
        else: # else we are into the longest file, just treat line as a single item tuple
             dest2.write("{}".format(line[0]))

Answer 2

如果您的文件长度相同或至少包含空白字段：

filea.csv

jan,feb,mar
80,50,52
74,73,56
,,

fileb.csv

apr,may,jun
64,75,64
75,63,63
77,88,99

脚本：

with open("filea.csv", "r") as source1, open("fileb.csv", "r") as source2, open("filec.csv","w") as dest:
    for line1, line2 in zip(source1, source2):
        dest.write(line1.strip()+','+line2)

如果您需要更紧凑的版本：

with open("filea.csv", "r") as source1, open("fileb.csv", "r") as source2, open("filec.csv","w") as dest:
    [dest.write(line1.strip()+','+line2) for line1, line2 in zip(source1, source2)]

结果（filec.csv）：

jan,feb,mar,apr,may,jun
80,50,52,64,75,64
74,73,56,75,63,63
,,,77,88,99

如何使用python将一个csv文件附加到另一个文件

2 个答案: