(seq, n, repetition=False)
Returns a generator of the n-sized variations of ``seq`` (size N).
    ``repetition`` controls whether items in ``seq`` can appear more than once;

    Examples
    ========

    variations(seq, n) will return N! / (N - n)! permutations without
    repetition of seq's elements:

        >>> from sympy.utilities.iterables import variations
        >>> list(variations([1, 2], 2))
        [(1, 2), (2, 1)]

    variations(seq, n, True) will return the N**n permutations obtained
    by allowing repetition of elements:

        >>> list(variations([1, 2], 2, repetition=True))
        [(1, 1), (1, 2), (2, 1), (2, 2)]

    If you ask for more items than are in the set you get the empty set unless
    you allow repetitions:

        >>> list(variations([0, 1], 3, repetition=False))
        []
        >>> list(variations([0, 1], 3, repetition=True))[:4]
        [(0, 0, 0), (0, 0, 1), (0, 1, 0), (0, 1, 1)]

    See Also
    ========

    sympy.core.compatibility.permutations
    sympy.core.compatibility.product
Returns a generator of the n-sized variations of ``seq`` (size N).
    ``repetition`` controls whether items in ``seq`` can appear more than once;
Returns a generator of the n - sized variations of seq ( size N ) . repetition controls whether items in seq can appear more than once ;
def variations(seq, n, repetition=False):
    """Returns a generator of the n-sized variations of ``seq`` (size N).
    ``repetition`` controls whether items in ``seq`` can appear more than once;

    Examples
    ========

    variations(seq, n) will return N! / (N - n)! permutations without
    repetition of seq's elements:

        >>> from sympy.utilities.iterables import variations
        >>> list(variations([1, 2], 2))
        [(1, 2), (2, 1)]

    variations(seq, n, True) will return the N**n permutations obtained
    by allowing repetition of elements:

        >>> list(variations([1, 2], 2, repetition=True))
        [(1, 1), (1, 2), (2, 1), (2, 2)]

    If you ask for more items than are in the set you get the empty set unless
    you allow repetitions:

        >>> list(variations([0, 1], 3, repetition=False))
        []
        >>> list(variations([0, 1], 3, repetition=True))[:4]
        [(0, 0, 0), (0, 0, 1), (0, 1, 0), (0, 1, 1)]

    See Also
    ========

    sympy.core.compatibility.permutations
    sympy.core.compatibility.product
    """
    if not repetition:
        seq = tuple(seq)
        if len(seq) < n:
            return
        for i in permutations(seq, n):
            yield i
    else:
        if n == 0:
            yield ()
        else:
            for i in product(seq, repeat=n):
                yield i
def variations ( seq , n , repetition = False ) : if not repetition : seq = tuple ( seq ) if len ( seq ) < n : return for i in permutations ( seq , n ) : yield i else : if n == 0 : yield ( ) else : for i in product ( seq , repeat = n ) : yield i