咨询：如何用Python正则表达式删除目录中含17的指定格式文件

Hey there! Let's get this file deletion task sorted out properly. First, let's recap your requirement: you need to delete all files in a target folder where the filename follows the pattern ??_????17*.* (must contain _ and 17, while skipping files with 18), with any file extension allowed.

Issues with Your Current Code #

Before diving into the fix, let's quickly go over what's not working in your existing code:

• The regex you wrote has incorrect escaping (like \\[_] instead of just _, and \\[1]\\[7] instead of 17)
• The matching function returns "Files don't exist!" when a match is found, which is the opposite of what you need
• You're trying to use testfolder.index(matching) which doesn't make sense (since os.listdir returns a list of strings, not objects with an index method that takes a function)
• The loop logic is broken—you can't call item.name() on a string filename

Simplest Solution: Use the glob Module #

You mentioned the glob module, and it's perfect here because it's designed exactly for matching file patterns. Here's a clean, working implementation:

import os
import glob

# Replace with your actual folder path
dir_name = "/Python/Test_folder"

# The glob pattern: ?? = 2 any chars, _ = literal underscore, ???? = 4 any chars, 17 = literal 17, * = any remaining chars
pattern = os.path.join(dir_name, "??_????17*")

# Iterate over all matching files
for file_path in glob.glob(pattern):
    # Make sure we're deleting a file, not a subfolder
    if os.path.isfile(file_path):
        print(f"Deleting: {file_path}")  # Optional: verify before deleting
        os.remove(file_path)

Alternative: Use Regular Expressions (For More Control) #

If you prefer using regex for more precise matching, here's a corrected version using re:

import os
import re

dir_name = "/Python/Test_folder"
# Regex pattern: ^ start of string, .{2} any 2 chars, _ literal, .{4} any 4 chars, 17 literal, .* any remaining chars
file_pattern = re.compile(r'^.{2}_.{4}17.*')

for filename in os.listdir(dir_name):
    file_path = os.path.join(dir_name, filename)
    # Skip directories, only process files
    if os.path.isfile(file_path):
        # Check if the filename matches our pattern
        if file_pattern.match(filename):
            print(f"Deleting: {file_path}")  # Optional: verify first
            os.remove(file_path)

Important Notes #

• Test First: Comment out the os.remove line and keep the print statement to make sure you're targeting the right files before deleting anything
• Backup: Always make a backup of your folder before running deletion scripts—better safe than sorry!
• Path Handling: Use absolute paths if you're unsure about the working directory, or use os.path.abspath() to convert relative paths
• Permissions: Ensure your script has write permissions for the target folder

内容的提问来源于stack exchange，提问作者Alexander Larionov