Text menu doesn't print properly

Question

The Problem has been solved. However, my account is new, so it won't let me answer the question. It seems that changing the instances of input() with raw_input() makes it work. I honestly have no clue why, but it may have something to do with the differences between 2 and 3.

I'm supposed to make a program that can calculate area and circumference. That part hasn't been so difficult.

However, the menu isn't working. The first part of the menu works just fine, but after you make a selection, it doesn't print what it's supposed to.

import math

print ("""
1) Calculate circumference
2) Calculate area
""")
ans = input("Enter 1, 2, or 0 to exit this program: ")
if ans == "1":
    diameter = float(input("Enter the diameter: "))
    if diameter > 0:
        circumference = (diameter*math.pi)
        print("The circumference is", circumference)
    else:
        print("Error: the diameter must be a positive number.")
if ans == "2":
    radius = float(input("Enter the radius: "))
    if radius > 0:
        area = ((radius**2)*math.pi)
        print("The area is", area)
    else:
        print("Error: the radius must be a postive number.")
if ans == "0":
    print("Thanks for hanging out with me!")
    quit()

Check the indentation of your original code against this. What you posted yields an `IndentationError`. — Brian, Sep 10 '13 at 23:28
@DennisMeng, It prints the first part of the menu, when I get the choices. However, when it gets to the if statements for ans, it stops working. — Brent Bennett, Sep 10 '13 at 23:30
@JeremyD & Brian It's apparently not my original indentation. I'll modify it. — Brent Bennett, Sep 10 '13 at 23:30
Try [raw_input\(\)](http://docs.python.org/2/library/functions.html#raw_input) instead of [input\(\)](http://docs.python.org/2/library/functions.html#input)? — Zoredache, Sep 10 '13 at 23:31
@Zoredache I think I love you. So much right now. Thanks, that totally worked. — Brent Bennett, Sep 10 '13 at 23:34
So your task now is to add an answer, with why that fixed it. — Zoredache, Sep 10 '13 at 23:36
@JeremyD, since you mentioned that, lets link over to the other question that give some details. http://stackoverflow.com/questions/4915361/whats-the-difference-between-raw-input-and-input-in-python3-x — Zoredache, Sep 10 '13 at 23:39
@JeremyD But your solution allows `input` to evaluate the `str` which results in some numeric value and then you convert it back to `str`. Hardly ideal. It masks an underlying issue OP has, rather than correct it. Not to mention how bad of an idea it is to evaluate user input... — Brian, Sep 10 '13 at 23:39
@Zoredache I totally agree with your comment, I just proposed something working quickly. — Jeremy D, Sep 10 '13 at 23:58
This question appears to be off-topic because it is about a mistake of the OP with using input/raw_input which was solved in the comments — joaquin, Sep 11 '13 at 05:53

Jeremy D · Answer 1 · 2013-09-11T00:00:08.737

After indenting properly, change if ans == "1" to str(ans) == "1" or ans == 1 and it should be fine.

This should work:

import math

print ("""
1) Calculate circumference
2) Calculate area
""")
ans = input("Enter 1, 2, or 0 to exit this program: ")
if str(ans) == "1":
    diameter = input("Enter the diameter: ")
    print diameter
    if float(diameter) > 0.0:
        circumference = (diameter*math.pi)
        print("The circumference is", circumference)
    else:
        print("Error: the diameter must be a positive number.")
....

PS: As mentionned in the comments, it works, but it is disgusting. We should only use ans == 1 or modify input to input_raw if you use python < python 3

score 0 · Answer 2 · answered Sep 10 '13 at 23:34

Your code's indentation shows the span of control of each 'if', 'for', or 'while'. You need to further indent the instructions under each major 'if' statement so that they only get executed when that 'if' statement is selected. Otherwise, everything that is at the leftmost indentation gets executed every time through the loop. For example, you should have something like:

if answer == '1':
....<statements that execute under condition 1>
elif answer == '2':
....<statements that execute under condition 2>

where I have emphasized the indentation with '....'.

He fixed that in his last edit a minute or so before you posted this. — Brian, Sep 10 '13 at 23:34

score 0 · Answer 3 · answered Sep 10 '13 at 23:35

0

The second if statement is not within the brackets of the first. this is true for both 1 and 2.

if ans == "1";
    diameter = float(input("enter the diameter: "))
    if diameter ....

answered Sep 10 '13 at 23:35

anon

1

score 0 · Answer 4 · answered Sep 10 '13 at 23:52

for me treating ans as integer worked. What I mean by treating ans as integer is instead of writing ans=="1" ,I wrote ans==1.it print corret cvalue. Check this code:

import math

print ("""
1) Calculate circumference
2) Calculate area
""")
ans = input("Enter 1, 2, or 0 to exit this program: ")
print ans
if ans ==1:
    diameter = float(input("Enter the diameter: "))
    if diameter > 0:
        circumference = (diameter*math.pi)
        print("The circumference is", circumference)
    else:
        print("Error: the diameter must be a positive number.")
if ans == 2:
    radius = float(input("Enter the radius: "))
    if radius > 0:
        area = ((radius**2)*math.pi)
        print("The area is", area)
    else:
        print("Error: the radius must be a postive number.")
if ans == 0:
    print("Thanks for hanging out with me!")
    quit()

Text menu doesn't print properly

4 Answers4