A complex number is a pair of real numbers a and b, most often written as a+bi, or a+ib, where i is called the imaginary unit and acts as a label for the second term. Mathematically, i2 = -1. Sometimes, j is used instead of i.
Here’s how a complex number is assigned to a variable:
>>> a=5+6j >>> a (5+6j) >>> type(a) <class 'complex'>
Python has a built-in function complex() which returns a complex data type.
complex(x) returns a complex number with x as real part and imaginary part as zero. complex(x,y) returns a complex number with x as real part and y as imaginary part.
>>> x=5 >>> complex(x) (5+0j) >>> x=5 >>> y=6 >>> complex(x,y) (5+6j)