How to catch these exceptions individually?

Question

I am writing a Python program that interfaces with Quickbooks. When connecting to Quickbooks, depending on the problem, I might get one of two common exceptions:

Answer 1

As soon as I posted I found the way to catch the exception in a non-generic manner in a question that appeared in the Related sidebar. Here is the way to capture these exceptions:

from pywintypes import com_error

except com_error as e:

Note that the differing reasons for the exception cannot be handled individually, so the return code must be examined inside the except clause by comparing the value of e.exceptinfo[5]:

except com_error as e:

    if e.excepinfo[5] == -2147220464:
        print('Please change the Quickbooks mode to Multi-user Mode.')

    elif e.excepinfo[5] == -2147220472:
        print('Please start Quickbooks.')

    else:
        raise e

I had considered marking this question as a dupe, but considering that none of the other related questions handle the situation of distinguishing between the different exceptions thrown under this single type, I leave this one as it addresses this issue and answers it.

Answer 2

Now pywintypes.error is BaseException.

There is no need to from pywintypes import com_error.

If you want to catch this exception. You can just catch BaseException

except BaseException as e: # to catch pywintypes.error
    print(e.args)

the exception's format likes this:

(0, 'SetForegroundWindow', 'No error message is available')

So If you want to examine the return code,use e.args[0] instead of e.exceptinfo[5]