Python/deep & shallow copy error

## Is this a major issue that you cannot fix?
I can fix it.
**Being a community driven documents of languages and tools,"YOUR" contributions
are also important.
If the issue you're reporting is trivial to report to maintainers why not contribute
to fix it. In that way, you will have contributed to an awesome open-source project.
The changes can be typo fix, fixing of data in examples or grammar fix. If you found it,
why not do it and take full credit for it?**

Make sure the issue title is prepended with '[language/lang-code]' if the language is
already on the site.
If it's a request for a new language, use: '[Request] [language/lang-code]'

Issues are always welcome. If you are able and willing, we welcome any pull requests
as this is a community powered project.

Issue line : # Make a one layer deep copy using slices
li2 = li[:] # => li2 = [1, 2, 4, 3] but (li2 is li) will result in false.

Locate the Python documentation entry containing “Make a one layer deep copy using slices” and inspect the surrounding deep- and shallow-copy examples. Compare the stated result and identity behavior with Python’s copy semantics, then update the example so the distinction is accurate and verify the edited documentation renders correctly.

Written by the indexing model from the issue text.