Difficulty adding two variables

Question

I've been learning python on codeacademy and I wanted to make a program that could help me with my homework and I started with pythagoras a²+b²=c² and it works perfectly on codeacademy but when I try it on the real python program it won't work and it closes before I can read what's wrong.

a = input ("what is a")
b = input ("what is b")

a = a*a
b = b*b
c =  a+b

from math import sqrt
c = sqrt (c)

print (c)

i know its pretty basic but im still learning also im not sure what version of python code academy is but im pretty sure the python program im useing is 3

I think this is more readable (and definitely much sorter): c = sqrt(a**2 + b**2) — Diego Herranz
– Diego Herranz, Commented Mar 1, 2013 at 19:47

b0bz · Accepted Answer · 2013-03-01 18:10:53Z

3

I believe you have a type conververtion problem here. So you need to convert it to an integer:

from math import sqrt
a = int(raw_input("what is a: "))
b = int(raw_input("what is b: "))

a = a*a
b = b*b
c = a+b

c = sqrt (c)
print (c)

Aslo, to not have to program close before you get to read the output, you would need to run the pythonfile from the terminal.

edited Mar 1, 2013 at 18:10

answered Mar 1, 2013 at 17:51

b0bz

2,2001 gold badge27 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Ben Abbott Over a year ago

thank you all for posting you all helped me with it and it does work now thanks!!

Ben Abbott Over a year ago

yeh i know than but i also fixed that with adding another input saying end

ApproachingDarknessFish · Accepted Answer · 2013-03-01 17:52:13Z

0

input returns a string (type str). in order for multiplication to work, you must create an integer (type int) from them like this:

a = int(input("what is a?"))
b = int(input("what is b?"))

or if you want the user to be able to type in decimals, use float:

a = float(input("what is a?"))
b = float(input("what is b?"))

answered Mar 1, 2013 at 17:52

ApproachingDarknessFish

14.4k8 gold badges42 silver badges81 bronze badges

Comments

Anuj Gupta · Accepted Answer · 2013-03-01 17:54:38Z

0

Python 2:

>>> a=input()
123
>>> a #is an int
123

Python 3:

>>> a=input()
123
>>> a #is a string
'123'

answered Mar 1, 2013 at 17:54

Anuj Gupta

10.6k3 gold badges32 silver badges32 bronze badges

Comments

cwallenpoole · Accepted Answer · 2013-03-01 18:03:40Z

You've got a type conversion issue. Cast to an float (or a int, here's a little about the difference between the two) and it will all be fine.

a = float(input ("what is a"))
b = float(input ("what is b"))

You should also look into using your Python interpreter. This is what I got when I tried to step through the code manually:

>>> a = input('what is a')
what is a3
>>> a*a # I put 3 in as my number, but it gave me the str value of '3'!
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: can't multiply sequence by non-int of type 'str'

I also recommend try...except to help give you better error messages. If you use while it will also make it so that you can make sure you have something to work with eg:

# Make them keep inputting "a" until they give you something 
# you can actually work with!
while 1:
    try:
        a = float(input ("what is a"))
        break
    except TypeError:
        print('That was not a number! please try again')

Note: this is not something which would happen in Python 2.x, as input can return an int.

djechlin · Accepted Answer · 2013-03-01 17:53:08Z

-1

If you run this in the python debugger you'll see what's happening line by line and be able to tell what line is the problem. I know you are green in Python but learning to use a debugger as soon as possible will make your learning process go so much faster. Try:

python -m pdb myscript.py

answered Mar 1, 2013 at 17:53

djechlin

61.1k40 gold badges173 silver badges300 bronze badges

Collectives™ on Stack Overflow

Difficulty adding two variables

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

5 Answers 5

2 Comments

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related