Python beginner having trouble running code

Question

For some reason this code will not seem to run in the interpreter. When I hit F5 nothing happens, not even the debugger seems to recognize it. I assume it has something to do with the class, as when removed the interpreter seems to recognize the rest of the code. Please tell me what I am doing wrong. Edit: I have restarted the interpreter multiple times, any other piece of code I try to load runs fine, just this one is having trouble.

edit: removed the initial print statement edit: fixed the indentation in the post code. edit: I have updated the code with fixes mentioned in the comments below; however, idle still does nothing when I try and run the code. I am using python 3.1.1 by the way.

class sorting_class:
    def __init__(self):
        self.globali = 0
        self.order = ['a', 'b', 'c', 'd']
        self.orderi = 0
        self.sortedlist = []
    def sort(self, array):
        carry, leave = []
        for arrayi in array:
            print ('run', arrayi)
            if self.order[self.orderi] == arrayi[self.globali]:
                carry.append(arrayi)
            else:
                if self.globali != 0:
                    leave.append(arrayi)
        return carry, leave
    def srt(self, array):
        globalii = 0
        carry, leave = my.sort(array)
        while len(self.sortedlist) != len(array):
            if len(carry) == 1:
                self.sortedlist.append(carry)
                arrayt = leave
                self.globali = 1
                self.orderi = 0
                carry, leave = my.sort(arrayt)
            elif len(carry) == 0:
                if len(leave) != 0:
                    arrayt = leave
                    self.globali = 1
                    self.orderi = 1
                    my.sort(arrayt)
                else:
                    self.arrayt 
                    globalii += 1
                    self.orderi = globalii
                    self.globali = 0
                    my.sort(arrayt)
                    self.orderi = 0
            else:
                arrayt = carry
                carry = []
                self.globali += 1
                carry, leave += my.sort(arrayt)
my = sorting_class()
x = ['ac', 'bc' ,'ab', 'da']
prin = my.srt(x)
print (prin)

Answer 1

The source highlighting should give you a hint. You either need to switch to double quotes, or escape the ' in won't.

Change

print ('Why won't this work?')   

to

print ('Why won\'t this work?')   

Answer 2

Seems that you have a problem with your indentation

...     my = sorting_class()
  File "<stdin>", line 45
    my = sorting_class()
                       ^
IndentationError: unindent does not match any outer indentation level
>>>     x = ['ac', 'bc' ,'ab', 'da']
  File "<stdin>", line 1
    x = ['ac', 'bc' ,'ab', 'da']
    ^
IndentationError: unexpected indent
>>>     my.srt(x)

once you get the indenting sorted you probably should consider having aprint statement somewhere

Answer 3

You're my = sorting_class() is defined inside the class. Take it out the class definition and you should be all set.

Answer 4

You reference my within your class methods when they are clearly not in scope anywhere. I'm not sure what this should even be referring to.

Also, it's indented one level too far.

Answer 5

I got the following error message when running your code:

  File "sss.py", line 44
    carry, leave += my.sort(arrayt)
SyntaxError: illegal expression for augmented assignment

You should get similar error messages too. BTW, I am using python 2.6.4 for testing.

Answer 6

I wonder if you're just having trouble working with IDLE. You mentioned elsewhere that the debugger just says "None". When I select "Debugger" from the IDLE interpreter window Debug menu, it pops up another window with the title "Debug Control", and it says "None" in that window.

That window is just a control panel. You still have to run the program, by choosing "Run" from the "Run" menu of the window that has your code in it. That will make something appear in the "Debug Control" window, and it will un-gray the buttons in that window ("Go", "Step", and so on) so you can actually use the debugger to run or step through your program.

---

When I cut & paste your code into an IDLE window and use the Run/Check Module option, it reports an illegal expression on line 44:

                carry, leave += my.sort(arrayt)

which looks pretty peculiar. The LHS is a tuple; tuples are immutable, you can't use += to modify them. Looks like you meant a plain equals sign there, since the sort method returns a tuple.

                carry, leave = my.sort(arrayt)

ETA: Ah, Stefan & John are also correct. You're sometimes using the name you used for your instance variable (my) instead of self when calling one method of the class from inside another.

Answer 7

There are too many errors in your code. Write down in plain English your requirements and start from scratch.

What are you trying to do? Is it:

x = ['ac', 'bc' ,'ab', 'da']
order = ['d', 'b', 'c', 'a']
assert len(order) == len(x)
x = [item for o, item in sorted(zip(order, x))]
print x
# -> ['da', 'bc', 'ab', 'ac']