Complex numbers

Python gives you complex numbers support out of the box. If you don't know what complex numbers are, they are numbers that can be expressed in the form a + ib where a and b are real numbers, and i (or j if you're an engineer) is the imaginary unit, that is, the square root of -1. a and b are called, respectively, the real and imaginary part of the number.

It's actually unlikely you'll be using them, unless you're coding something scientific. Let's see a small example:

>>> c = 3.14 + 2.73j
>>> c.real  # real part
3.14
>>> c.imag  # imaginary part
2.73
>>> c.conjugate()  # conjugate of A + Bj is A - Bj
(3.14-2.73j)
>>> c * 2  # multiplication is allowed
(6.28+5.46j)
>>> c ** 2  # power operation as well
(2.4067000000000007+17.1444j)
>>> d = 1 + 1j  # addition and subtraction as well
>>> c - d
(2.14+1.73j)