Symbols in Python.

symbol.py

class symbol(object):
    _symbols = {}

    def __new__(cls, name):
        if name not in symbol._symbols:
            symbol._symbols[name] = object.__new__(cls, name)
        return symbol._symbols[name]

    def __init__(self, name):
        self.name = name

assert symbol('foo') == symbol('foo'), 'symbols with same name must be equal'
assert symbol('foo') != symbol('bar'), 'symbols with different names must not be equal'