Get type instance from string in Python

Question

So, I need to cast a value to a given type:

if 'int' == type_name:
    value = int(value)
elif 'str' == type_name:
    value = str(value)
...

Is there a way to do that generically? E.g.:

type_instance = get_type_instance(type_name)
value = type_instance(value)

I'm using Python 2.7, but would be interested in a Python 3.X solution as well.

Update:

Here's the solution I'm using:

class Token:

    def __init__(self, type_name, value):
        self.type = type_name
        self.value = __builtins__[type_name](value) # not safe

This is just a toy parser. Don't use in production!

Answer 1

If you need only __builtins__ types you can do

value = getattr(__builtins__, type_name)(value)

Answer 2

Build a dict

TYPES = {
  'int' : int,
  'str' : str,
...
}

value = TYPES[type_name](value)