How to print an existing variable by passing its name

Question

For example:

class abc():
    def __init__(self):
        self.john = 'a'
        self.mike = 'b'

    def d(self, x):
        print(self.x)

m = abc()
# m.d('john')
# m.d(john)

If I try running m.d('john') I get 'AttributeError: 'abc' object has no attribute 'x'' and if I try running m.d(john) I get 'NameError: name 'john' is not defined'. How can I modify this so that it works?

[Here is a solution from a similar question](https://stackoverflow.com/questions/18425225/getting-the-name-of-a-variable-as-a-string) — Farid Fakhry, Jul 22 '22 at 15:28
@SembeiNorimaki: Did you actually try that? I think you'll be disappointed. — Scott Hunter, Jul 22 '22 at 15:30

score 2 · Answer 1 · answered Jul 22 '22 at 15:28

2

Use Python's getattr().

class abc():
    def __init__(self):
        self.john = 'a'
        self.mike = 'b'

    def d(self, x):
        print(getattr(self, x))

m = abc()
m.d('john')

answered Jul 22 '22 at 15:28

Ryan Zhang

1,856
9
19

1

what are the chances we wrote the exact same code at the exact same time with the exact same first name LOL – Ryan Jul 22 '22 at 15:30
1

Non-zero, obviously! – Ryan Zhang Jul 22 '22 at 15:31
This should go on some Stack Overflow hall-of-fame. I'm willing to bet that this is the first time this has happened. – Ryan Zhang Jul 22 '22 at 15:32

score 2 · Accepted Answer · answered Jul 22 '22 at 15:29

2

Use getattr(). It allows you to get an attribute from a string.

Code:

class abc():
    def __init__(self):
        self.john = 'a'
        self.mike = 'b'

    def d(self, x):
        print(getattr(self, x))

m = abc()
m.d('john')

Output:

answered Jul 22 '22 at 15:29

Ryan

1,081
6
14

How to print an existing variable by passing its name

2 Answers2