How is the output 4.0?

Question

print(abs(4j))
print(abs(4a))
print(abs(4b))
output: 4.0
SyntaxError
SyntaxError

Answer 1

4j is a notation of a complex number with 0 as real and 4 as imaginary part.

Absolute value of a complex number is its distance from the Origin (center) on the complex plane.
https://www.varsitytutors.com/hotmath/hotmath_help/topics/absolute-value-complex-number

Answer 2

In Python, 4j is a complex number. The full representation would be 0+4j, where the real part is 0 and the imaginary part 4j. As indicated, 4a and 4b are just syntax errors. To find the absolute value of that imaginary number, find the absolute length of the line between the points on the real and imaginary axes. The Pythagorean theorem is used: sqrt(0*0 + 4*4) = 4.0

Answer 3

Python has support for complex data types.. Its of the form (a +bj)
So first one is valid complex number .
But later 2 are invalid identfiers..

edit:

https://www.pythonforbeginners.com/data-types/complex-numbers-in-python