pySCG: Adding explanation of the 'is' operator to CWE-595

[s19110]

Addresses issue #714

[myteron]

provided example01.py code in the md for the obsevered issues around numbers and strings to explain memory optimistation related isses.

[dwiley258]

Just wondering if we would want to have the outputs for both the non compliant and the compliant solutions like we have for the example?

[myteron]

Just wondering if we would want to have the outputs for both the non compliant and the compliant solutions like we have for the example?

We never made a decision on having output examples mandatory. I would prefer if the reader is running the scripts them self to experience the issue. I tent to provide example output when:

• I need the output to explain what is happening
• The output differs to much between different CPython installations.
• Behavior is to unpredictable as we see with multiprocessing examples.