Added source code for 'Swap nodes in pairs' problem in Python

[abhinav5481]

Related Issuse

• Swap nodes in pairs

Closes: #286

Describe the changes you've made

Added source code for 'Swap nodes in pairs' problem in Python

Type of change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [x] Code style update (formatting, local variables)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [x] This change requires a documentation update

How Has This Been Tested?

Local machine

Describe if there is any unusual behaviour of your code(Write NA if there isn't)

NA

Checklist:

• [x] My code follows the style guidelines of this project.
• [x] I have performed a self-review of my own code.
• [x] I have commented my code, particularly in hard-to-understand areas.
• [x] I have made corresponding changes to the documentation.
• [x] My changes generate no new warnings.
• [x] I have added tests that prove my fix is effective or that my feature works.
• [x] New and existing unit tests pass locally with my changes.

Please review my code.

[abhinav5481]

Hi @ankitapuri Please review my PR.

[abhinav5481]

Hi @ankitapuri Please review my PR. As today is the last date for CRossWoc. Please

[abhinav5481]

Its not giving any output

It is a functional problem. problem was intended to write a function to swap nodes.

[ankitapuri]

I know its a leetcode ques , but its answer should depend on the input not . U can see the test cases as well .