almost.py

import unittest, numbers

class AlmostNumber:
    def __init__(self, number, delta):
        self.number = number
        self.delta = delta
        
    def __eq__(self, other):
        return abs(self.number-other) < self.delta        
        
    def __repr__(self):
        return repr(self.number)

def almost(obj, delta=1e-6):
    if isinstance(obj, numbers.Number):
        return AlmostNumber(obj, delta)
    if isinstance(obj, dict):
        return {almost(x, delta): almost(y, delta) for x, y in obj.items()}
    if isinstance(obj, (list, tuple, set)):
        return type(obj)(almost(x, delta) for x in obj)
    return obj
        
class AlmostTest(unittest.TestCase):
    def test_example(self):
        self.assertEquals(almost([1, 2]), [1.0, 1.99999999999])
        self.assertEquals(almost({'a':1, 'b':2}), {'a':1.0, 'b':1.99999999999})
        
unittest.main()