Source code for dgenies.lib.decorators

class Singleton:
    """
    Define a singleton (design pattern)
    """

    def __init__(self, klass):
        self.klass = klass
        self.instance = None

    def __call__(self, *args, **kwds):
        if self.instance is None:
            self.instance = self.klass(*args, **kwds)
        return self.instance