Python - 基于文件前缀合并多个文件

Question

Python 2.7

我有多个文件：

文件 A_01.txt 文件内容：aaaa

文件 A_02.txt 文件内容：bbbb

文件 B_01.txt 文件内容：aaaB

文件 B_02.txt 文件内容：bbbB

文件 D_01.txt 文件内容：aaaD

文件 D_02.txt 文件内容：bbbD

我需要根据文件前缀创建“合并”文件，

对于以 A_0 开头的文件，创建合并文件merged_A.txt 并将所有文件的内容以 A_0 开头，

merged_B.txt 用于以 B_ 开头的文件

所有文件都一样

# get all files in folder 

files = os.listdir("C:\\MTA\\mta") 

for filename in files:
    #get prefix
   prefix = filename[0:3]

# open destination file to merge individual files into 

   with open(os.path.join("C:\\MTA\mta", "merged" + "_" + prefix + ".txt"), 'w') as outfile:
       # go through all files and merge it into outfile
       for file in files:
           with open(os.path.join("C:\\MTA\mta", filename)) as infile:
             outfile.write(infile.read())
           outfile.write("--------------\n")

以上代码，生成合并文件，但是，两个合并文件都包含所有文件的内容

files = os.listdir("C:\\MTA\\mta") 

for filename in files:
    #get prefix
   prefix = filename[0:3]

# open destination file to merge individual files into 

   with open(os.path.join("C:\\MTA\mta", prefix + "file.siem"), 'w') as outfile:
       # go through all files and merge it into outfile
       #for filename in files:
           with open(os.path.join("C:\\MTA\mta", filename)) as infile:
             outfile.write(infile.read())
           outfile.write("--------------\n")

此版本只将一个文件的内容写入合并文件中

Answer 1

每次读取文件时，您都在写入一个新文件，您需要改为追加。您还有一个不必要的嵌套 for 循环来读取文件，而您可以在外部循环中读取它们。这应该有效：

import os

# get all files in folder 

files = os.listdir("C:\\MTA\\mta") 

for filename in files:
    #get prefix
    prefix = filename[0:2]


# open destination file to merge individual files into 

    with open(os.path.join("C:\\MTA\\mta", "merged" + "_" + prefix + ".txt"), 'a') as outfile:
       # go through all files and merge it into outfile
        with open(os.path.join("C:\\MTA\\mta", filename)) as infile:
            outfile.write(infile.read())
        outfile.write("--------------\n")