No there is not. You cannot declare a variable or value as constant in Python. Just don't change it.
If you are in a class, the equivalent would be:
class Foo(object): CONST_NAME = "Name"
if not, it is just
CONST_NAME = "Name"
You can also use namedtuple to create constants:
>>> from collections import namedtuple
>>> Constants = namedtuple('Constants', ['pi', 'e'])
>>> constants = Constants(3.14, 2.718)
>>> constants.pi 3.14
>>> constants.pi = 3
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
AttributeError: can't set attribute