setting user input to variable name

Question

I am using python and would like to know if it would be possible to ask the user for the name of a variable and then create a variable with this name. For example:

my_name = input("Enter a variable name") #for example the user could input orange
#code to set the value of my_name as a variable, say set it to the integer 5
print(orange) #should print 5 if the user entered orange

I know it can be done using a dictionary but I would like to know whether this is possible without creating an additional object. I am using python 3. Thanks.

EvenLisle · Accepted Answer · 2015-04-23T13:05:41.870

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You can use the dictionary returned by a call to globals():

input_name = raw_input("Enter variable name:") # User enters "orange"
globals()[input_name] = 4
print(orange)

If you don't want it defined as a global variable, you can use locals():

input_name = raw_input("Enter variable name:") # User enters "orange"
locals()[input_name] = 4
print(orange)

edited Apr 23 '15 at 13:05

answered Apr 23 '15 at 13:03

EvenLisle

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Thanks, It works. However do I always have to do it with globals()? – Hadi Khan Apr 23 '15 at 13:05
I'm not aware of any simpler way to achieve what you ask than via `globals()` or `locals()`. – EvenLisle Apr 23 '15 at 13:11
`locals` isn't guaranteed to work. – Veedrac Apr 24 '15 at 05:13
If the assignment and use are in the same lexical scope, then yes, it is. – EvenLisle Apr 24 '15 at 08:06
How do you access this variable later in the code without knowing the user input beforehand? – Lilwen Nov 10 '20 at 17:12

score 0 · Answer 2 · edited May 23 '17 at 10:24

0

If your code is outside a function, you can do it by modifying locals.

my_name = raw_input("Enter a variable name")  # Plain input() in Python 3
localVars = local()
localVars[my_name] = 5

If you're inside a function, it can't be done. Python performs various optimizations within functions that rely on it knowing the names of variables in advance - you can't dynamically create variables in a function.

More information here: https://stackoverflow.com/a/8028772/901641

edited May 23 '17 at 10:24

Community

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answered Apr 23 '15 at 13:05

ArtOfWarfare

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This answer works outside a function. You said that it is not possible to do it inside a function but the answer by @EvenLisle works inside a function as well. Could you please explain why this happens? – Hadi Khan Apr 23 '15 at 13:11
@AbdulHadiKhan: You're modifying globals in his case. Python takes a lot longer to access global variables than local variables. – ArtOfWarfare Apr 23 '15 at 13:13

setting user input to variable name

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