using docstring in python
#A docstring is a string literal that occurs as the first statement in a module,
#function, class, or method definition. Such a docstring becomes the __doc__ special
#attribute of that object.
#They serve as documentation or explanation to a statement in a function, class or
#method definition. They are kept in a triple quotation mark.
def complex(real=0.0, imag=0.0):
"""Form a complex number.
Keyword arguments:
real -- the real part (default 0.0)
imag -- the imaginary part (default 0.0)
"""
if imag == 0.0 and real == 0.0:
return complex_zero
...