How to print name of class in Python

Question

I am trying to find the syntax to print the name of my classes. Given the following:

#!/usr/bin/python

class a:
    whatever  = 0

foo = a()
bar = a()
listOfClasses = [foo,bar]

for l in listOfClasses:
    print l 
    #I'm trying to find the syntax to print the name of the class (eg foo and bar)

Answer 1

From your example, you're looking for the name of the instance (foo and bar). In a nutshell, there isn't a way to do it since there could be multiple named variables pointing to the same instance.

If you're looking for the name of the class (i.e. a), you could use l.__class__.__name__. However, this is not totally bullet-proof either:

In [10]: class A(object): pass
   ....: 

In [11]: A().__class__.__name__
Out[11]: 'A'

In [12]: Z = A

In [13]: Z().__class__.__name__
Out[13]: 'A'

Answer 2

It's not possible to get this information, because in Python objects do not have names as such (only references to objects have names). Consider:

foo = a()
bar = foo # bar is now another name for foo

lst = [foo, bar] # both elements refer to the *same* object

In this case, what would your hypothetical "name" function print for each element of lst? To show that both elements refer to the same object:

print [id(x) for x in lst]

will print the same id twice.

Answer 3

You can use this: instance.__class__.__name__

so in your case: a = foo.__class__.__name__

or b = bar.__class__.__name__

a and b are of type string.