Adding implementation of stack using python in python section

[robinsingh-ai]

Is your feature request related to a problem? Please describe. Hey @rish-singhal I would like to add implementation of stacks with two more programs which will work concept of stack (like infix to postfix and integer to binary conversion using stack) in Python language as the solution for the same is missing in the repo.

Do you want to work on it I will implement this in python language

Kindly Assign me this under GSSOC 21

[robinsingh-ai]

hey @rish-singhal assign me this issue if its available