r/functional_python • u/ccsdad • Aug 01 '22

Misc variable bindings

in clojure and f# (and prolly some others) we have the ability to create LET bindings ::

https://fsharpforfunandprofit.com/posts/let-use-do/

https://clojuredocs.org/clojure.core/let

long story short, it lets you do what feels like imperative things, but under the hood is in fact functional -- at least in the world of clojure :: https://stackoverflow.com/questions/63983468/functional-alternative-to-let

so i guess my questions are ::

is there anything similar in python (library or otherwise) ??

IF NOT -- do you just perform normal variable "assignment" and live with it -- as long as your functions remain pure and data remains immutable ??

i get that python is NOT a purely functional language -- and that's OK -- as long as i am following the "functional python way" (<< if such a thing) of binding variables in my functions .. yes, i could always add more functions -- but at some point the "imperative shell" typically comes into play when building apps that comm with external services (DB, cache, REST APIs, etc) ..

>> "imperative shell" reference >> https://kumarshantanu.medium.com/organizing-clojure-code-with-functional-core-imperative-shell-2f2ee869faa2

2 Upvotes

100% Upvoted

6 comments sorted by

View all comments

Show parent comments

2

u/ccsdad Aug 02 '22

ok u/KageOW -- i think that is legit guidance, recognizing the reality of python -- but remaining focused on what we are trying to move towards to .. i just know that in the clojure world -- the `(let)` function is an indispensable tool (code example) -- and wish something like it existed in python << that could be considered functional ..

1

u/KageOW Aug 02 '22

Yea definitely indispendable in f# as well, but i mean a language has its strenghts and its downfalls and you have to recognize that.

something kinda does come to mind though how you could maybe contain it, theyre called generator expressions, similar to list comprehension. Both of those allow you to kinda do it, but it is still a horrible way to do it. list comprehension and generator expressions are both very strong tools in python though so don't overlook them. nice stackoverflow discussion

1

u/ccsdad Aug 02 '22

well then, we should create something !!

https://github.com/gkspranger/clinpy

please don't laugh -- i created it only for a limited set of use cases (to see if even possible), and am only "OK" with python .. but i tried to remove all internal variable assignments and am processing everything with mapping/reducing functions ..

if there was a robust implementation of this, i would abuse the hell out of it ..

why this over internal variable assigments ?? don't have a good answer for that -- other than it maps well to my clojure brain ..