Improved some grammar in datastructures.py : "as" --> "like" and added commas.
Improved some grammar in datastructures.py : "as" --> "like" and added commas.

See:
https://www.quora.com/What-is-the-difference-between-just-like-and-just-as-in-grammar
https://www.quora.com/Whats-the-difference-between-as-and-like

mitsuhiko/werkzeug,pallets/werkzeug,pallets/werkzeug,mitsuhiko/werkzeug,fkazimierczak/werkzeug,fkazimierczak/werkzeug,fkazimierczak/werkzeug,pallets/werkzeug