写入TXT文件时触发FileNotFoundError问题排查求助

Let's break down why you're hitting this error even though the target directory exists, and walk through actionable fixes step by step.

Possible Causes & Solutions #

1. Windows Path Length Limit #

Windows has a default maximum path length of 260 characters. Looking at the error path:

C:/Users/Info/Desktop/Dissertation/Impression Management/Analyse/10 CEO Transcripts/Interviews WORK/3032771020/Earnings Calls Texts/2017/February 22, 2017_Event Brief of Q4 2016 Arris International PLC Earnings Call Q4 2016 and Acquisition Update - Final.pdf.txt

This is almost certainly exceeding that limit, which triggers the FileNotFoundError even if the directory is valid.

Fix:

• Enable long path support (requires Windows 10 1607+/Windows Server 2016+):
  1. Open Registry Editor (regedit)
  2. Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\FileSystem
  3. Set the LongPathsEnabled DWORD value to 1 (create it if it doesn't exist)
• Alternatively, shorten the filename or directory structure for this specific case.

2. Race Condition Between Directory Check & File Write #

Your code checks if the directory exists, but there's a tiny window where the directory could be deleted/moved after the check but before opening the file. While you confirm the directory exists, this is a common oversight in file handling.

Fix:
Replace the directory check with os.makedirs (which ensures the directory exists right before writing) and use os.path.join for more reliable path construction:

import os

# Build directory path safely
dir_path = os.path.join(
    'C:/Users/Info/Desktop/Dissertation/Impression Management/Analyse',
    '10 CEO Transcripts/Interviews WORK',
    str(deal_no),
    'Earnings Calls Texts',
    str(year)
)

# Create directory if it doesn't exist (no error if it does)
os.makedirs(dir_path, exist_ok=True)

# Build full file path
file_path = os.path.join(dir_path, f'{fulldate}_{file}.txt')

# Write to file
with open(file_path, 'w') as filehandle:
    for item in textlist_new:
        filehandle.write(f'{item}\n')

3. Hidden Invalid Characters in Filename #

While your filename looks valid at a glance, variables like fulldate or file might contain invisible characters (like non-breaking spaces) or Windows-reserved symbols that break the path.

Fix:
Sanitize the filename to remove/replace invalid characters:

import re

def sanitize_filename(filename):
    # Replace all Windows-invalid filename characters with underscores
    return re.sub(r'[<>:"/\\|?*]', '_', filename)

# Clean variables before building the path
clean_fulldate = sanitize_filename(fulldate)
clean_file = sanitize_filename(file)
file_path = os.path.join(dir_path, f'{clean_fulldate}_{clean_file}.txt')

4. Permission Restrictions #

It's possible that for this specific directory, your user account lacks write permissions (even if other files in the parent structure worked).

Fix:
Right-click the target directory > Properties > Security tab > Verify your user account has "Write" permissions enabled.

Final Takeaway #

The most likely issue here is the long path length, since your code worked for shorter filenames/directories. Start by enabling long path support, then switch to using os.makedirs and os.path.join for more robust, cross-platform path handling.

内容的提问来源于stack exchange，提问作者xxgaryxx