How can I get the name of an object?

Nathan_Fellman_1084 0
Viewed 175438

Is there any way to get the name of an object in Python? For instance:

my_list = [x, y, z] # x, y, z have been previously defined

for bla in my_list:
    print "handling object ", name(bla) # <--- what would go instead of `name`?
    # do something to bla

Edit: Some context:

What I'm actually doing is creating a list of functions that I can specify by the command line.

I have:

def fun1:
    pass
def fun2
    pass
def fun3:
    pass

fun_dict = {'fun1': fun1,
            'fun2': fun2,
            'fun3': fun3}

I get the name of the function from the commandline and I want to call the relevant function:

func_name = parse_commandline()

fun_dict[func_name]()

And the reason I want to have the name of the function is because I want to create fun_dict without writing the names of the functions twice, since that seems like a good way to create bugs. What I want to do is:

fun_list = [fun1, fun2, fun3] # and I'll add more as the need arises

fun_dict = {}
[fun_dict[name(t) = t for t in fun_list] # <-- this is where I need the name function

This way I only need to write the function names once.

introspection python
18 Answers

I know This is late answer.

  1. To get func name , you can use func.__name__
  2. To get the name of any python object that has no name or __name__ method. You can iterate over its module members.

Ex:.

# package.module1.py

obj = MyClass()



# package.module2.py
import importlib
def get_obj_name(obj):
   mod = Obj.__module__ # This is necessary to 
   module = module = importlib.import_module(mod)
   for name, o in module.__dict__.items():
      if o == obj:
         return name

Performance note: don't use it in large modules.

user_23909920

Python has names which are mapped to objects in a hashmap called a namespace. At any instant in time, a name always refers to exactly one object, but a single object can be referred to by any arbitrary number of names. Given a name, it is very efficient for the hashmap to look up the single object which that name refers to. However given an object, which as mentioned can be referred to by multiple names, there is no efficient way to look up the names which refer to it. What you have to do is iterate through all the names in the namespace and check each one individually and see if it maps to your given object. This can easily be done with a list comprehension:

[k for k,v in locals().items() if v is myobj]

This will evaluate to a list of strings containting the names of all local "variables" which are currently mapped to the object myobj.

>>> a = 1
>>> this_is_also_a = a
>>> this_is_a = a
>>> b = "ligma"
>>> c = [2,3, 534]
>>> [k for k,v in locals().items() if v is a]

['a', 'this_is_also_a', 'this_is_a']

Of course locals() can be substituted with any dict that you want to search for names that point to a given object. Obviously this search can be slow for very large namespaces because they must be traversed in their entirety.

user_33117280

Based on what it looks like you're trying to do you could use this approach.

In your case, your functions would all live in the module foo. Then you could:

import foo

func_name = parse_commandline()
method_to_call = getattr(foo, func_name)
result = method_to_call()

Or more succinctly:

import foo

result = getattr(foo, parse_commandline())()
user_42336580

Hi there is one way to get the variable name that stores an instance of a class is to use

locals()

function, it returns a dictionary that contains the variable name as a string and its value

user_155195000
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