Partition

partition.py

@Function                                                                                                                                                                 
def partition(f, xs):                                                              
    """ Partition a sequence according to satisfaction of a predicate.             
                                                                                   
    The result is a tuple in which the first component is a sequence of            
    unsatisfying elements and the second is a sequence of satisfying elements.  
    """                                                                            
    result = ([], [])                                                              
    for x in xs:                                                                   
        result[1 if f(x) else 0].append(x)                                         
    return result