cmath.e    Returns Euler's number (2.7182...)
cmath.inf    Returns a floating-point positive infinity value
cmath.infj    Returns a complex infinity value
cmath.nan    Returns floating-point NaN (Not a Number) value
cmath.nanj    Returns coplext NaN (Not a Number) value
cmath.pi    Returns PI (3.1415...)
cmath.tau    Returns tau (6.2831...)