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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def crossover(cross):
 """Return an inspyred crossover function based on the given function. This function generator takes a function that operates on only two parent candidates to produce an iterable sequence of offspring (typically two). The generator handles the pairing of selected parents and collecting of all offspring. The generated function chooses every odd candidate as a 'mom' and every even as a 'dad' (discounting the last candidate if there is an odd number). For each mom-dad pair, offspring are produced via the `cross` function. The given function ``cross`` must have the following signature:: offspring = cross(random, mom, dad, args) This function is most commonly used as a function decorator with the following usage:: @crossover def cross(random, mom, dad, args):
 # Implementation of paired crossing pass The generated function also contains an attribute named ``single_crossover`` which holds the original crossover function. In this way, the original single-set-of-parents function can be retrieved if necessary. """

    @functools.wraps(cross)
    def inspyred_crossover(random, candidates, args):
        if len(candidates) % 2 == 1:
            candidates = candidates[:-1]
        moms = candidates[::2]
        dads = candidates[1::2]
        children = []
        for i, (mom, dad) in enumerate(zip(moms, dads)):
            cross.index = i
            offspring = cross(random, mom, dad, args)
            for o in offspring:
                children.append(o)
        return children
    inspyred_crossover.single_crossover = cross
    return inspyred_crossover