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+ 1

How to create a dynamic variable in python

name = 0 basically what it should do is : name1 = 0 name2 =0 name3 = 0 Is this possible?

11th Apr 2022, 9:39 AM
Edward Marais
Edward Marais - avatar
12 Answers
+ 2
Lothar Fixed. x = 1 while x < 4: exec("name{}={}" .format(x, x)) x += 1 If You want to test the New variables, write this before the addition: exec("print(name{})" .format(x))
13th Apr 2022, 3:01 PM
Luis André Baroni Istúriz
Luis André Baroni Istúriz - avatar
+ 5
Edward Marais , to do this task we can generate the variable names like *var* + a number inside a loop. then we have to add this name together with the value we like to assign to the locals() dict. # create variables dynamically lst = [10, 24, 37] for ndx, i in enumerate(lst): locals()["var"+str(ndx)]=i print(var2) print(locals()) # shows the locals() dict with the variables instead of using numbers from a list, we can also use input() function. >>> instead of using the above procedure, we can also use a list or a dictionary and store the input values in it. this makes it easier to handle the variable & and values during execution. may be you can show us what you like to achieve so that we can recommend the best way. thanks!
11th Apr 2022, 11:17 AM
Lothar
Lothar - avatar
+ 3
I'm still wondering why one would not just use some container type for it, like Oma Falk suggested.
14th Apr 2022, 11:39 AM
HonFu
HonFu - avatar
+ 2
Edward Marais , with the description in my post you should be able to do a test if it is possible or not. i still believe that using data structures like list or dictionary can do what you need. but anyway it is your decision - good success!
12th Apr 2022, 5:29 PM
Lothar
Lothar - avatar
+ 2
Luis Baroni x = 1 while <condition>: exec "name%s = %s" %(x) # <<< creates syntax error. can you check this? x += 1
13th Apr 2022, 7:03 AM
Lothar
Lothar - avatar
+ 2
Lothar The sintax error ocurred because I forgot the parentheses. :) I change the formatting of the text to make it more understable.
13th Apr 2022, 3:03 PM
Luis André Baroni Istúriz
Luis André Baroni Istúriz - avatar
+ 2
Luis Baroni , this looks very nice now.
13th Apr 2022, 3:44 PM
Lothar
Lothar - avatar
+ 2
name = [] name.append(0) name.append(1) print(name[0]) print(name[1])
13th Apr 2022, 6:07 PM
Oma Falk
Oma Falk - avatar
+ 2
Edward Marais , my last try for this post. since you still have not given more details / code samples it is still guessing for all who are trying to help you: names = {'human1': 0, 'human2': 2, 'alien1': 3, 'human3': 1, 'human4': 0} print(len(names)) # "variables" in total print("number of humans", len([ctg for ctg in names.keys() if ctg.startswith("human")])) # 4 print("number of aliens", len([ctg for ctg in names.keys() if ctg.startswith("alien")])) # 1 names['alien2'] = 1 print("number of aliens", len([ctg for ctg in names.keys() if ctg.startswith("alien")])) # 2
13th Apr 2022, 7:36 PM
Lothar
Lothar - avatar
+ 2
HonFu "[...] Python doesn't try to prevent you from shooting yourself in the foot [...]". 🙃 http://stupidpythonideas.blogspot.com/2013/05/why-you-dont-want-to-dynamically-create.html?m=1
15th Apr 2022, 9:09 AM
Lisa
Lisa - avatar
+ 1
@Lothar basically what i want to know is if you can create a variable that can create new variables to store data for example ( Human = 0 ) and lets say it was in a for loop that runs n times that n number is how many human variables that will be created and stores data . I'm just curious if this is possible
12th Apr 2022, 9:00 AM
Edward Marais
Edward Marais - avatar
0
Edward Marais , you should try with this: x = 1 While <condition>: exec "name%s = %s" %(x) x += 1
13th Apr 2022, 2:46 AM
Luis André Baroni Istúriz
Luis André Baroni Istúriz - avatar