Possible to capture cgitb style output in a try/except section?

Tue Jul 26 10:04:56 EDT 2016

Malcolm Greene wrote:

> Is there a way to capture cgitb's extensive output in an except clause
> so that cgitb's detailed traceback output can be logged *and* the except
> section can handle the exception so the script can continue running?
>  
> My read of the cgitb documentation leads me to believe that the only way
> I can get cgitb output is to let an exception propagate to the point of
> terminating my script ... at which point cgitb grabs the exception and
> does its magic.

I see Steven has already answered while I was composing an example script. 
Rather than throwing it away I'll give it below:

#!/usr/bin/env python3
import cgitb
cgitb.enable()

print("Content-type: text/html\r\n\r\n")
print("<html><body>")
print("hello world<br/>")
for expr in [
        "1 + 1",
        "1 / 0", # handled in the except clause
        "2 * 2",
        "1 x 2", # handled by sys.excepthook set via cgitb.enable()
        "3 * 3"  # not reached
]:
    try:
        print(expr, "=", eval(expr))
    except ZeroDivisionError:
        cgitb.Hook().handle()
    print("<br/>")

print("</body></html>")