Stop python from going to the very last statement
Question: I am currently writing a program that will solve the pythagorean theorem.
However, I have a bug in the program. Whenever I put in a negative number for
length a or b, it prints out "A cannot be less than zero" but goes ahead and
solves for C anyway and prints out the length of C even though the user hasn't
input b yet. How can I make it so when the user inputs a negative number it
prints out the statement "A cannot be less than zero" and then loops again to
inputting a length for the side, instead of how it is now where after it
prints out the statement it redirects to the end?

Here is my code:

    
    
     import math
        print"This program will solve the pythagorean theorem for you"
        unit=raw_input('Enter the unit you will be using')
        a=float(raw_input('Enter the length of side a'))
        if a<=0:
          print"A cannot be less than zero"
        else:
            b=float(raw_input('Enter the length of side b'))
        if b<=0:
          print"B cannot be less than zero"
        else:
            c2=(a**2)+(b**2)
            c=math.sqrt(c2)
            c=str(c)
            print "The length of side C is: "+ c + " " + unit + "."
    


Answer: You missed one indentatino level. Try it like this :

    
    
    if a<0:
      print"A cannot be less than zero"
    else:
        b=raw_input('Enter the length of side b')
        b=float(b)
        if b<0:
            print"B cannot be less than zero"
        else:
            c2=(a**2)+(b**2)
            c=math.sqrt(c2)
            c=str(c)
            print "The length of side C is: "+ c + " " + unit + "."
    

