expand your script with :
print(a) # the vector itself
print(a.length()) # vector´s length
results should be:
Vectorposition : 0.44 and 0.89
Vectorlength : 1
all fine ;)
change the vectors starting position to (1,1) and take also a paper and pen and draw it into coordinate system. take a closer look. what would you suggest the vectors length, if x is pointing one to the right and y one up? More the one i guess.
Next Questing would be if your are normalizing this Vector(1,1) to a lenght of one, how would these affect x and y? Try to do this on your corrdinate system by your own just with (how is this in englisch called? ;)) (triangle) ruler.
maybe also helpfull would be to take a look at Pythagoras' theorem and trigonometry in general before starting to do some vector math.