def IF(test, tv, fv=None):
    if test:
        return tv
    else:
        return fv
Return Stirling number S(n, k) of the first or second (default) kind.
dataset/ETHPy150Open kdart/pycopia/aid/pycopia/aid.py/IF--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/functions/combinatorial/numbers.py/stirling