Question

I need to obtain the error number from an error that has occurred in Python.

Ex; When trying to transfer a directory via the Paramiko package, an error is caught with this piece of code:

try:
    sftp.put(local_path,target_path)    
except (IOError,OSError),errno:
    print "Error:",errno

For which I get the output,

Error: [Errno 21] Is a directory

I want to utilize the error number to go into some more code to transfer the directory and the directory contents.

Answer 1

Thanks for clarifying your question.

Most Exceptions in Python don’t have “error numbers”. One exception (no pun intended) are HTTPError exceptions, for example:

import urllib2 
try:
   page = urllib2.urlopen("some url")
except urllib2.HTTPError, err:
   if err.code == 404:
       print "Page not found!"
   else:
       ...

Another exception (as noted by bobince) are EnvironmentErrors:

import os
try:
   f=open("hello")
except IOError, err:
   print err
   print err.errno
   print err.strerror
   print err.filename

outputs

[Errno 2] No such file or directory: 'hello'
2
No such file or directory
hello