我有c++ /Obj-C背景,我刚刚发现Python(写了大约一个小时)。 我正在写一个脚本递归地读取文件夹结构中的文本文件的内容。

我的问题是,我写的代码将只工作于一个文件夹深度。我可以在代码中看到为什么(见#hardcoded path),我只是不知道如何使用Python,因为我对它的经验只是全新的。

Python代码:

import os
import sys

rootdir = sys.argv[1]

for root, subFolders, files in os.walk(rootdir):

    for folder in subFolders:
        outfileName = rootdir + "/" + folder + "/py-outfile.txt" # hardcoded path
        folderOut = open( outfileName, 'w' )
        print "outfileName is " + outfileName

        for file in files:
            filePath = rootdir + '/' + file
            f = open( filePath, 'r' )
            toWrite = f.read()
            print "Writing '" + toWrite + "' to" + filePath
            folderOut.write( toWrite )
            f.close()

        folderOut.close()

当前回答

确保你理解os.walk的三个返回值:

for root, subdirs, files in os.walk(rootdir):

具有以下含义:

root:被“遍历”的当前路径 subdirs:目录类型根目录下的文件 files:根目录下(不是subdirs目录下)的非directory类型的文件

请使用os.path.join而不是用斜杠连接!您的问题是filePath = rootdir + '/' + file -您必须连接当前“行走”的文件夹,而不是最上面的文件夹。filePath = os。path。加入(根、文件)。顺便说一句,“文件”是内置的,所以你通常不使用它作为变量名。

另一个问题是你的循环,应该是这样的,例如:

import os
import sys

walk_dir = sys.argv[1]

print('walk_dir = ' + walk_dir)

# If your current working directory may change during script execution, it's recommended to
# immediately convert program arguments to an absolute path. Then the variable root below will
# be an absolute path as well. Example:
# walk_dir = os.path.abspath(walk_dir)
print('walk_dir (absolute) = ' + os.path.abspath(walk_dir))

for root, subdirs, files in os.walk(walk_dir):
    print('--\nroot = ' + root)
    list_file_path = os.path.join(root, 'my-directory-list.txt')
    print('list_file_path = ' + list_file_path)

    with open(list_file_path, 'wb') as list_file:
        for subdir in subdirs:
            print('\t- subdirectory ' + subdir)

        for filename in files:
            file_path = os.path.join(root, filename)

            print('\t- file %s (full path: %s)' % (filename, file_path))

            with open(file_path, 'rb') as f:
                f_content = f.read()
                list_file.write(('The file %s contains:\n' % filename).encode('utf-8'))
                list_file.write(f_content)
                list_file.write(b'\n')

如果你不知道,文件的with语句是一种简写:

with open('filename', 'rb') as f:
    dosomething()

# is effectively the same as

f = open('filename', 'rb')
try:
    dosomething()
finally:
    f.close()

其他回答

同意Dave Webb的观点。Walk将为树中的每个目录生成一个项。事实上,您不需要关心子文件夹。

这样的代码应该可以工作:

import os
import sys

rootdir = sys.argv[1]

for folder, subs, files in os.walk(rootdir):
    with open(os.path.join(folder, 'python-outfile.txt'), 'w') as dest:
        for filename in files:
            with open(os.path.join(folder, filename), 'r') as src:
                dest.write(src.read())

使用os.path.join()来构造你的路径-这样更整洁:

import os
import sys
rootdir = sys.argv[1]
for root, subFolders, files in os.walk(rootdir):
    for folder in subFolders:
        outfileName = os.path.join(root,folder,"py-outfile.txt")
        folderOut = open( outfileName, 'w' )
        print "outfileName is " + outfileName
        for file in files:
            filePath = os.path.join(root,file)
            toWrite = open( filePath).read()
            print "Writing '" + toWrite + "' to" + filePath
            folderOut.write( toWrite )
        folderOut.close()

我发现下面的方法是最简单的

from glob import glob
import os

files = [f for f in glob('rootdir/**', recursive=True) if os.path.isfile(f)]

使用glob('some/path/**', recursive=True)获取所有文件,但也包括目录名。添加if os.path.isfile(f)条件只过滤现有文件

操作系统。Walk默认情况下执行递归遍历。对于每个dir,它从根目录开始生成一个3元组(dirpath, dirnames, filename)

from os import walk
from os.path import splitext, join

def select_files(root, files):
    """
    simple logic here to filter out interesting files
    .py files in this example
    """

    selected_files = []

    for file in files:
        #do concatenation here to get full path 
        full_path = join(root, file)
        ext = splitext(file)[1]

        if ext == ".py":
            selected_files.append(full_path)

    return selected_files

def build_recursive_dir_tree(path):
    """
    path    -    where to begin folder scan
    """
    selected_files = []

    for root, dirs, files in walk(path):
        selected_files += select_files(root, files)

    return selected_files

如果你想要一个给定目录下的所有路径的平面列表(比如find。在壳中):

   files = [ 
       os.path.join(parent, name)
       for (parent, subdirs, files) in os.walk(YOUR_DIRECTORY)
       for name in files + subdirs
   ]

若要只包含基本目录下文件的完整路径,请省略+ subdirs。