python cmath constants

1cmath.e	Returns Euler's number (2.7182...)
2cmath.inf	Returns a floating-point positive infinity value
3cmath.infj	Returns a complex infinity value
4cmath.nan	Returns floating-point NaN (Not a Number) value
5cmath.nanj	Returns coplext NaN (Not a Number) value
6cmath.pi	Returns PI (3.1415...)
7cmath.tau	Returns tau (6.2831...)