Is it possible to assign a variable as a value in a dictionary (for Python)?

Question

for variables 'a' and 'b' in dictionary 'dict1' is it possible to later call variable 'a' using its key given in 'dict1' to assign a value to it??

 a=""
 b=""
 dict1= {0:a,1:b}

    dict1[0] = "Hai"    #assign a value to the variable using the key

    print(a)            #later call the variable```

You cannot change what a name refers to, except by direct assignment to the name. This is distinct from *mutating* the object a name refers to, but a `str` is immutable. — chepner, Apr 15 '20 at 11:56
Yes. `dict1[0]` and `a` are two entirely separate names for the `str`; assigning to `dict1[0]` has no more affect on the value of `a` than would `b = a; b = "Hai"`. — chepner, Apr 15 '20 at 12:04

score 0 · Answer 1 · answered Apr 15 '20 at 11:58

0

No, when you do the assignment {key:value}, the value doesn't refer to the original variable, so mutating either one will not affect the other.

answered Apr 15 '20 at 11:58

Louis Charles

1
1
1

is there a way we can do this? or someway to get this function done – user13320463 Apr 15 '20 at 12:07

SebNik · Answer 2 · 2020-04-15T12:38:20.590

0

The variable is not set automatically, what you could do is:

def update_dic(a,b):
   dict1={0:a, 1:b}
   return dict1

def update_vars(dict1):
   return dict1[0],dict1[1]

Every time you call the first function your dictionary is getting updated, and for the second time you always get a and b back.

edited Apr 15 '20 at 12:38

answered Apr 15 '20 at 12:01

SebNik

880
3
10
21

Do you know of any way to access a set of variables by a set of keys?? – user13320463 Apr 15 '20 at 12:14
I think the only way is with two functions i put the above in my answer. – SebNik Apr 15 '20 at 12:38
This is can be used if a, b is known /given as input, but what I am looking for is where the key is given as input and to change the value of a or be according the key provided. – user13320463 Apr 15 '20 at 18:32

score 0 · Answer 3 · answered Apr 15 '20 at 14:06

You could do something similar using a class to store your variables and the indexing dictionary:

class Variables():
    def __init__(self):
        self.varIndex = dict()

    def __getitem__(self,index):
        return self.__dict__[self.varIndex[index]]

    def __setitem__(self,index,value):
        self.__dict__[self.varIndex[index]] = value

variables = Variables()

variables.a = 3
variables.b = 4
variables.varIndex = {0:"a",1:"b"}
variables[0] = 8
print(variables.a) # 8

user13320463 · Answer 4 · 2020-04-15T19:48:27.510

We can do this by using two dictionaries with the same amount of variables:

This allows to access the variable 'a' using the key '0' and then altering its value using 'dict2' and later get the value by calling 'a'.

however remember that the variables need to written as string i.e. in quotes, it doesn't work when used as a regular variable.

 dict1= {0:'a',1:'b'}
 dict2={'a':'x','b':'y'}

 dict2[dict1[0]]="Hai"    #assign a value to the variable using the key

 print(dict2['a'])          #later call the variable ````

Is it possible to assign a variable as a value in a dictionary (for Python)?

4 Answers4