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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 combinations(seq, k):
 """ Return j length subsequences of elements from the input iterable. This version uses Numpy/Scipy and should be preferred over itertools. It avoids the creation of all intermediate Python objects. Examples -------- [[0 1] [0 2] [1 2]] [[0 1] [0 2] [1 2]] """

    from itertools import combinations as _combinations, chain
    from scipy.special import comb

    count = comb(len(seq), k, exact=True)
    res = np.fromiter(chain.from_iterable(_combinations(seq, k)),
                      int, count=count*k)
    return res.reshape(-1, k)