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scipy.special.

# comb

scipy.special.comb(N, k, *, exact=False, repetition=False)

  The number of combinations of N things taken k at a time.

  This is often expressed as “N choose k”.

  Parameters:
    N int, ndarray

      Number of things.

    k int, ndarray

      Number of elements taken.

    exact bool, optional

      For integers, if exact is False, then floating point precision is used, otherwise the result is computed exactly.

      Deprecated since version 1.14.0: `exact=True` is deprecated for non-integer N and k and will raise an error in SciPy 1.16.0

    repetition bool, optional

      If repetition is True, then the number of combinations with repetition is computed.

  Returns:
    val int, float, ndarray

      The total number of combinations.

  See also

  `binom`

    Binomial coefficient considered as a function of two real variables.

  Notes

  - Array arguments accepted only for exact=False case.

  - If N < 0, or k < 0, then 0 is returned.

  - If k > N and repetition=False, then 0 is returned.

  Examples

      >>> import numpy as np
      >>> from scipy.special import comb
      >>> k = np.array([3, 4])
      >>> n = np.array([10, 10])
      >>> comb(n, k, exact=False)
      array([ 120.,  210.])
      >>> comb(10, 3, exact=True)
      120
      >>> comb(10, 3, exact=True, repetition=True)
      220