Python: Unable to stop this program's sentinel loop

Question

SO I'm making a program about hockey players playing and I will record their goals.

Here's what should happen:

Who scored? 4
Who scored? 5
Who scored? 6
Who scored? 4
Who scored? 3
Game still going?(y/n) y
Who scored? 3
Who scored? 2
Who scored? 5
Who scored? 2
Who scored? 3
Game still going?(y/n) n

Creating a histogram from values: 
Element Goals Histogram
      1     0 
      2     2 **
      3     2 ***
      4     2 **
      5     2 **
      6     1 *
      7     1 *
      8     0 
      9     0 
     10     0

Here is my code:

def info():
    ranking = [0,0,0,0,0,0,0,0,0,0,0]
    survey = []
    return ranking,survey
def info2(survey):   
    x = ''
    for i in range(0,5):
        x = int(input("Who scored?"))           
        survey.append(x)
    again(x)
    return survey
def info3(ranking,survey):
    for i in range(len(survey)):
        ranking[survey[i]]+=1
    return ranking, survey

def again(x):
    y = input("Game still on? y/n").lower()
    if y == "yes" or y == "y":
        info()
    elif y == "n" or y =="no":
        hg(x)


#create histogram
def hg():
    print("\nCreating a histogram from values: ")
    print("%3s %5s %7s"%("Element", "Goals", "Histogram"))

#start from element 1 instead of 0
    for i in range(len(ranking)-1):
        print("%7d %5d %-s"%(i+1, ranking[i+1], "*" * ranking[i+1]))

def main():
    x,y = info()
    a = info2(y)
    d = again(x)
    b,c = info3(x,a)
    z = hg(x)
main()

When I run this as it is, I get the Who scored thing, and I enter 'y' on the y/n and it works, but when I enter y/n and i put n, it prints the "element goals histogram" then throws the following:

Traceback (most recent call last):
 line 48, in <module>
    main()
 line 44, in main
    a = info2(y)
 line 17, in info2
    again(x)
 line 29, in again
    hg(x)
 line 39, in hg
    for i in range(len(ranking)-1):
NameError: name 'ranking' is not defined

printing it after `survey.append(x)` shows that it is not a list like i want it to be. :s — Registered User, Jan 16 '15 at 04:27
I think `input` is not the function you want. When writing a program it's helpful to test small parts of it, to make sure they work correctly, before putting it all together. For example, try `x = int(input("Who scored?"))` by itself. — Lack, Jan 16 '15 at 04:31
Oh my mistake, I just noticed the [python-3.x] tag. If it works as you want by itself, keep it in. — Lack, Jan 16 '15 at 04:34
This is a good read: http://stackoverflow.com/questions/954834/how-do-i-use-raw-input-in-python-3-1 — Lack, Jan 16 '15 at 04:35
are you sure this is your code as you are running it? looks like it will throw an error when you enter 'n' because your `hg` function takes one input, but you're calling it like `hg()` from the `again` function. — zehnpaard, Jan 16 '15 at 04:37
This part `"1234567890".split()` is completely not necessary. You just converting it to a list in there. — , Jan 16 '15 at 04:43
You should change every use of 'x' and 'y' to descriptive variable names. Also change your function names. Naming things is really important to readable code. — Håken Lid, Jan 16 '15 at 04:48
true. but is that essential now or can i proceed still? @HåkenLid — Registered User, Jan 16 '15 at 04:49

score 2 · Answer 1 · edited Feb 21 '15 at 18:25

2

x = input("Game still on? y/n").lower

instead should be:

x = input("Game still on? y/n").lower()

edited Feb 21 '15 at 18:25

answered Jan 16 '15 at 04:42

mchant

320
1
8

Voted me down for that? I was still typing. – mchant Jan 16 '15 at 04:46

khampson · Accepted Answer · 2015-01-16T04:58:10.157

There are a couple issues that I see with the code...

First, you've got lower instead of lower() in your again() function. This binds the function itself to x instead of calling it and assigning its return value.

Also, your hg() function expects an argument, but you don't pass one in here. The ranking defined in info() is local to that function, and not visible from hg().

Edit in response to OP after OP's code was updated based on my comments above:

Also, there are issues with your handling of the exit case in again(). I think you shouldn't call hg() at all there, and instead return the answer to a separate variable in info2().

So that code for those two functions would then look something like this:

def info2(survey):
    x = ''
    ans = 'y'

    while ans in ('y', 'yes'):
        for i in range(0,5):
            x = int(input("Who scored?"))
            survey.append(x)
        ans = again()
    return survey

def again():
    x = input("Game still on? y/n").lower()
    if x == "yes" or x == "y":
        info()

    return x

Note the use of the additional variable, and the pass.

Edit in response to 2nd comment from OP:

info3() is unchanged. I added again() and info2() with my changes. You would keep info3() as is (at least as regards this particular question).

Also, since my change just had pass in the No case, it can actually be removed entirely. Just check for the Yes case, and otherwise return (an else isn't even required in this particular case).

When I run the code with the changes I mentioned, it appears to work as required. This is example output:

Who scored?1
Who scored?1
Who scored?1
Who scored?2
Who scored?2
Game still on? y/ny
Who scored?3
Who scored?3
Who scored?3
Who scored?2
Who scored?2
Game still on? y/nn

Creating a histogram from values: 
Element Goals Histogram
      1     3 ***
      2     4 ****
      3     3 ***
      4     0 
      5     0 
      6     0 
      7     0 
      8     0 
      9     0 
     10     0

info3() is not needed anymore? – Registered User Jan 16 '15 at 04:47 — Registered User, Jan 16 '15 at 04:47

score 0 · Answer 3 · answered Jan 16 '15 at 06:06

I'm not sure what all of the functions and variables were supposed to do. It's easier to debug and understand code if you use sensible names for functions and variables.

from collections import OrderedDict

def main():
    list_of_players = [str(number) for number in range(1, 11)]
    ranking = play(list_of_players)
    print_histogram(ranking)

def play(list_of_players):
    ranking = OrderedDict([(player, 0) for player in list_of_players])
    while True:
        for i in range(5):
            player = input('Who scored? ')
            try:
                ranking[player] += 1
            except KeyError:
                print('Not a player')
        if input('Game still going?(y/n) ').lower() in ['n', 'no']:
            return ranking

def print_histogram(ranking):
    template = '{player:^7} {goals:^7} {stars}'
    print('\nCreating a histogram from values: ')
    print(template.format(player='Element', goals='Goals', stars='Histogram'))
    for player, goals in ranking.items():
        print(template.format(player=player, goals=goals, stars='*' * goals))

if __name__ == '__main__':
    main()

it gives name error when I select `y` if Game still going – user123 Jan 16 '15 at 06:44 — user123, Jan 16 '15 at 06:44

Python: Unable to stop this program's sentinel loop

3 Answers3