Some new number classes

[lighthaus205]

Hey,
I created some new number classes and wanted to share them. I might keep on working on some more.
With these classes it's possible to add / multiply multiple dependent fields and to create a RandomFloat where the maximum is dependent on another field.

class RelativeNumberAddFields(DependentField):
    """
    Returns a number relative to another number field.

    Example:
    >>> import testdata
    >>> class Foo(testdata.DictFactory):
    ...     a = testdata.CountingFactory(1)
            b = testdata.CountingFactory(5)
            c = testdata.CountingFactory(10)
    ...     d = testdata.RelativeNumberAdd('a', 'b', 'c')
    >>> [i for i in Foo().generate(3)]
    [{'a': 1, 'b': 5, 'c': 10, 'd': 16},
     {'a': 2, 'b': 6, 'c': 11, 'd': 19},
     {'a': 3, 'b': 7, 'c': 12, 'd': 22}]
    """
    def __init__(self, *args):
        super(RelativeNumberAddFields, self).__init__(args)
        self._args = args
    
    def __call__(self):
        super(RelativeNumberAddFields, self).__call__()
        result = 0
        for value in self._args:
            result += self.depending_fields[value]
        return result

class RelativeNumberMultiplyFields(DependentField):
    """
    Returns a number relative to another number field.

    Example:
    >>> import testdata
    >>> class Foo(testdata.DictFactory):
    ...     a = testdata.CountingFactory(1)
            b = testdata.CountingFactory(5)
            c = testdata.CountingFactory(10)
    ...     d = testdata.RelativeNumberAdd('a', 'b', 'c')
    >>> [i for i in Foo().generate(3)]
    [{'a': 1, 'b': 5, 'c': 10, 'd': 50},
     {'a': 2, 'b': 6, 'c': 11, 'd': 132},
     {'a': 3, 'b': 7, 'c': 12, 'd': 252}]
    """
    def __init__(self, *args):
        super(RelativeNumberMultiplyFields, self).__init__(args)
        self._args = args
    
    def __call__(self):
        super(RelativeNumberMultiplyFields, self).__call__()
        result = 1
        for value in self._args:
            result = result * self.depending_fields[value]
        return result

class ConditionalMaxRandomFloat(DependentField):
    """
    Returns a Float between `minimum` and `maximum`
    """
    def __init__(self, minimum, maximum):
        super(ConditionalMaxRandomFloat, self).__init__([maximum])
        self._maximum = maximum
        self._minimum = minimum

    def __call__(self):
        super(ConditionalMaxRandomFloat, self).__call__()
        return (random.random() * (self.depending_fields[self._maximum] - self._minimum)) + self._minimum