How can I get variable from a different file using user input?

Question

I'm working on a fun project with my friend and we're trying to figure out how to get a specific variable from a file using user input.

Example:

In pokemonList.py file

charmander = "fire"
squirtle = "water"

In main.py file

import pokemonList
pokemon = input("select a pokemon: ")
print(pokemonList.pokemon)

When I try that the program thinks I'm trying to get a variable called "pokemon" from the file. Is there any way to do this?

You want to use a dict. Or perhaps something more advanced like the configparser package. — 0x5453
– 0x5453, Commented Oct 16, 2020 at 17:26
Does this answer your question? How do I create a variable number of variables? — ggorlen
– ggorlen, Commented Oct 16, 2020 at 17:36

Andrew · Accepted Answer · 2020-10-16 17:26:11Z

2

Assuming that names are unique, I think a dictionary is a sensible approach:

in pokemonList.py:

pokemon = {"charmander" : "fire",
           "squirtle" : "water"}

in main.py:

import pokemonList

pokemon = input("select a pokemon: ")
print(pokemon, " ", pokemonList.pokemon[pokemon])

answered Oct 16, 2020 at 17:26

Andrew

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1 Comment

DontAsk_ Over a year ago

Thank you for your quick answer! We've swapped all the variables and it works like a charm!

Yuval.R · Accepted Answer · 2020-10-16 17:36:11Z

0

There are a couple of ways to achieve what you need.

Instead of saving the variables just as variables, save them as a dictionary, like this:

pokemonList.py:

pokemon = {"charmander": "fire",
           "squirtle": "water"}

main.py:

import pokemonList

pokemon = input("select a pokemon: ")
print(pokemonList.pokemon[pokemon])

You can use the eval function to get the values (very unsafe and not recommended):

pokemonList.py:

charmander = "fire"
squirtle = "water"

main.py:

import pokemonList
pokemon = input("select a pokemon: ")
print(eval("pokemonList."+pokemon))

edited Oct 16, 2020 at 17:36

answered Oct 16, 2020 at 17:30

Yuval.R

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5 Comments

ggorlen Over a year ago

The eval approach is poor design. Code shouldn't be tied down to what its variable names are literally and eval is a security hole, not to mention slow. Looking the user input in globals is a bit better but still pretty awful.

ShapeOfMatter Over a year ago

Option 2 is extremely unsafe. Probably it's "ok" for your current task, but not doing things like eval(input()) is the bare minimum of program security.

Yuval.R Over a year ago

Correct, this is why it is the second way, but I will add that this is unsafe and not recommended.

ggorlen Over a year ago

Or just remove it entirely ;-)

ggorlen Over a year ago

Here's an example string you can input to see the severity here: charmander.index(eval('__import__("os").system("echo I wiped your harddrive")')).

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