pythonexceptionbase64binascii

Python: How to catch this Error (can't source error name) - binascii.Error

I'm using the base64 module for the b64decode() function, however certain strings of text throw this error: 

'binascii.Error: Incorrect Padding'.

I understand that this is because the strings are not of length multiple of 4, a requirement of base64 encoded text.

Rather than just adding '='s to the end of the string to make it a multiple of 4, I want to catch the error and simply state that the string is not base64 encoded. It works using a general 'except:', however I want to catch the specific error, but I can't find out the same of the error, as it is not very specific as with other errors, and 'except binascii.Error:' is apparently undefined. Help?

Solution

  • The exception type is stored in binascii.Error, there's multiple ways of catching the exception:

    # 1. you can import the binascii module
import binascii
try:
    pass
except binascii.Error as err:
    pass


# 2. or you can use the binascii from base64's namespace

try:
    pass
except base64.binascii.Error as err:
    pass


# 3. or you can use __import__ to do a temp import

try:
    pass
except __import__('binascii').Error as err:
    pass