How to Troubleshoot SFTPError: No such file: File Existence and Path Issues in Paramiko

Paramiko’s SFTP client raises SFTPError: No such file when the specified path is invalid or inaccessible. This guide provides a systematic approach to diagnosing and resolving path and file-existence issues in SFTP operations, drawing on best practices and PDF documentation on SSH and POSIX path semantics.

1. Verify Remote Path Syntax

Ensure correct use of forward slashes and no trailing spaces:

# Incorrect: backslashes or trailing slash
remote_path = "C:\\folder\\file.txt"
remote_path = "/home/user/directory/"
# Correct:
remote_path = "/home/user/directory/file.txt"
  

import posixpath
remote_path = posixpath.join('/home/user', 'file.txt')
    

2. Check File Existence with stat

Before opening or downloading, verify existence using sftp.stat():

try:
    sftp.stat(remote_path)
except IOError as e:
    print(f"File not found: {remote_path}")
    # handle missing file
  

3. Handle Symlinks and Directories

Remote symlinks or directories can cause mis-detection:

from stat import S_ISDIR, S_ISLNK

attr = sftp.lstat(remote_path)
if S_ISLNK(attr.st_mode):
    # resolve symlink
    real_path = sftp.readlink(remote_path)
    print("Resolved symlink to", real_path)
elif S_ISDIR(attr.st_mode):
    print("Path is a directory, not a file")
else:
    print("Path is a regular file")
  

4. Normalize Paths

Remove redundant components and handle relative paths:

def normalize(path):
    # collapse . and .. components
    return posixpath.normpath(path)

remote_path = normalize("/home/user/../user/file.txt")
  

5. Manage Permissions

Insufficient permissions can also trigger “No such file”:

try:
    sftp.open(remote_path, 'rb')
except IOError as e:
    if e.errno == 13:
        print("Permission denied for", remote_path)
    else:
        raise
  

6. Implement Retry Logic for Transient Issues

import time

def retry_stat(path, retries=3):
    for i in range(retries):
        try:
            return sftp.stat(path)
        except IOError:
            time.sleep(1)
    raise FileNotFoundError(f"Unable to stat {path} after retries")
  

7. Logging and Debugging

Enable Paramiko logging for SFTP details:

import logging
logging.basicConfig(level=logging.DEBUG)
paramiko.util.log_to_file('paramiko.log')
  

8. Summary Checklist

1. Use forward slashes and posixpath for remote paths.
2. Verify file existence with sftp.stat() and handle IOError.
3. Detect and resolve symlinks and directories via lstat() and readlink().
4. Normalize paths with posixpath.normpath().
5. Check and adjust permissions; handle errno 13.
6. Implement retries for transient network or server delays.
7. Enable Paramiko debug logging to inspect SFTP exchanges.