This module is always available. It provides access to mathematical functions for complex numbers. The functions are:
The module also defines two mathematical constants:
Note that the selection of functions is similar, but not identical, to that in module math . The reason for having two modules is, that some users aren't interested in complex numbers, and perhaps don't even know what they are. They would rather have math.sqrt(-1) raise an exception than return a complex number. Also note that the functions defined in cmath always return a complex number, even if the answer can be expressed as a real number (in which case the complex number has an imaginary part of zero).