How to use user input to access a variable?

Question

I am creating a program in which I would like to prompt users for NYC boroughs, and use a general GPS coordinate of said borough. Part of my code for this is

df.loc[0,'BOROUGH'] = input('Borough:\n')
manhattan = [40.7831, -73.9712]
brooklyn = [40.6782, -73.9442]
staten_island = [40.5795, -74.1502]
queens = [40.7282, -73.7949]
bronx = [40.8448 ,-73.8648]

I would like to now use the input response to access the appropriate coordinates. For example, if the user inputs "Manhattan," I can use some variant of input().lower() to grab the corresponding borough data.

I know from this answer that, if I want to create a variable using input, I can do that. Is there a way to access a variable?

Why not use one dictionary with keys like "manhattan" rather than different variables? In any event, `globals()` is a dictionary, so you can use it to access variables as well as define this. But -- that is almost always a sign of poor design. — John Coleman, Dec 06 '20 at 19:57
@JohnColeman Your comment reminds me of the classic quote from Gandalf in Lord of the Rings: "Throw yourself in next time, and rid us of your stupidity." How I didn't think of this is beyond me. Thanks. — Yehuda, Dec 06 '20 at 19:59
You don’t call variables. You must be thinking of something else. — quamrana, Dec 06 '20 at 19:59
@quamrana Please forgive the terminology error. I'm relatively new to this whole programming thing. — Yehuda, Dec 06 '20 at 20:03
@quamrana Invented it on the fly as I was writing the question, because I've heard the term "call" related to programming stuff. Let's blame heuristics and laziness. — Yehuda, Dec 06 '20 at 20:07
Oh, I see. I hadn’t fully realised that people really did that. — quamrana, Dec 06 '20 at 20:11
@quamrana I accept the dubious honor of introducing you to the beginner's side of SO ;) — Yehuda, Dec 06 '20 at 20:13
Short answer: `gps_coords = globals()[input('Borough:\n')]` (has no error handling). — martineau, Dec 06 '20 at 21:42

quamrana · Accepted Answer · 2020-12-06T21:56:24.997

This is one way of picking some data from a collection given a user input:

boroughs = {'manhattan':[40.7831, -73.9712],
'brooklyn': [40.6782, -73.9442],
'staten_island': [40.5795, -74.1502],
'queens': [40.7282, -73.7949],
'bronx': [40.8448 ,-73.8648]
}

while True:
    borough = input('Please enter a borough name: ').lower()
    if borough in boroughs:
        print(f'GPS coordinates of {borough} are {boroughs[borough]}')
    else:
        print(f'Unknown borough: {borough}')

How to use user input to access a variable?

1 Answers1