Question

in my program I have undefined variable somewhere:

global name 'cmd' is not defined

How can I pull out the line number where the variable is being used?

I know where the error is (cmd versus self.cmd). The question is how to get the line number (or why it isnt shown).

Since I was catching error, I had to traceback.print_exc() to get line numbers

Answer 1

Where are you running your program? a Python stacktrace usually looks like this:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'cmd' is not defined

As you can see it indicates the line where the error is happening.