python cmath constants
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...)