如何打开包含其他文件夹中的文件的文件夹

Question

for example,

Inside of Folder X there are Folders A, B, and C which contain each files.

How can I create a loop that will go inside of each Fodler A, B, and C, and open the file i need in write mode to make some changes?

Answer 1

To modify the content of different file walking through its subdirectories, you can use os.walk and fnmatch - to choose the proper file format that you want to modify!

import os, fnmatch
def modify_file(filepath):
    try:
        with open(filepath) as f:
            s = f.read()
        s = your_method(s) # return modified content
        if s: 
            with open(filepath, "w") as f: #write modified content to same file
                print filepath
                f.write(s)
                f.flush()
            f.close()
    except:
        import traceback
        print traceback.format_exc()

def modifyFileInDirectory(directory, filePattern):
    for path, dirs, files in os.walk(os.path.abspath(directory), followlinks=True):
        for filename in fnmatch.filter(files, filePattern):
            modify_file(filename)


modifyFileInDirectory(your_path,file_patter)

Answer 2

If all of the files have the same name (say, result.txt ), the loop is fairly simple:

for subdir in ('A', 'B', 'C'):
    path = 'X/{}/result.txt'.format(subdir)
    with open(path, 'w') as fp:
        fp.write("This is the result!\n")

Or, perhaps:

import os.path

for subdir in ('A', 'B', 'C'):
    path = os.path.join('X', subdir, 'result.txt')
    with open(path, 'w') as fp:
        fp.write("This is the result!\n")

Update:

With the additional requirements listed in the comments, I recommend you use glob.glob() , like so:

import os.path
import glob

for subdir in glob.glob("X/certain*"):
    path = os.path.join(subdir, "result.txt")
    with open(path, 'w') as fp:
        fp.write("This is the result\n")

In the above example, the call to glob.glob() will return a list of all of the subdirectories of X that begin with the literal text "certain". So, this loop might create, successively, "X/certainA/result.txt" and "X/certainBigHouse/result.txt", assuming that those subdirectories already exist.