In Python, imaginary numbers are characterized by suffixing a floating-point number with the letter j, for example, z = 5.2j. A complex number is formed by the sum of a real number and an imaginary number, for example, z = 3.5 + 5.2j.
While in mathematics the imaginary part is expressed as a product of a real number b with the imaginary unit 
, the Python way of expressing an imaginary number is not a product: j is just a suffix to indicate that the number is imaginary.
This is demonstrated by the following small experiment:
b = 5.2
z = bj # returns a NameError
z = b*j # returns a NameError
z = b*1j # is correct
The method conjugate returns the conjugate of z:
z = 3.2 + 5.2j
z.conjugate() # returns (3.2-5.2j)
