Gamma x
This calls Python's built-in math.gamma function, which computes the gamma function of x.
math.gamma
i1 : Gamma toPython 5 o1 = 24.0 o1 : PythonObject of class float
i2 : Gamma toPython 0.5 o2 = 1.7724538509055159 o2 : PythonObject of class float
The source of this document is in Python/doc/special.m2:71:0.