tan x
This calls Python's built-in math.tan function, which computes the tangent of x.
math.tan
i1 : tan toPython 0 o1 = 0.0 o1 : PythonObject of class float
i2 : tan toPython (pi / 4) o2 = 0.9999999999999999 o2 : PythonObject of class float
The source of this document is in Python/doc/trig.m2:182:0.