Why isn't this code working how I want it to?

Mark Lawrence breamoreboy at yahoo.co.uk
Sat Oct 12 07:13:55 EDT 2013


On 12/10/2013 12:03, reubennottage at gmail.com wrote:
> On Saturday, October 12, 2013 10:20:24 AM UTC+1, Peter Otten wrote:
>> reubennottage at gmail.com wrote:
>>
>>
>>
>>> I've been working on a program and have had to halt it due a slight
>>
>>> problem. Here's a basic version of the code:
>>
>>>
>>
>>> a = 'filled'
>>
>>> b = 'filled'
>>
>>> c = 'empty'
>>
>>> d = 'empty'
>>
>>> e = 'filled'
>>
>>> f = 'empty'
>>
>>> g = 'filled'
>>
>>>
>>
>>> testdict = {a : 'apple' , b : 'banana' , c : 'cake' , d : 'damson' , e :
>>
>>> 'eggs' , f : 'fish' , g : 'glue'}
>>
>>
>>
>> You have duplicate keys here, which becomes obvious when you spell out the
>>
>> values
>>
>>
>>
>> testdict = {"filled": "apple", "filled": "banana", ...}
>>
>>
>>
>> When you do that, the last value ("banana") wins, all others (e. g. "apple")
>>
>> are dropped.
>>
>>
>>
>>> Now what I want to do, is if a variable is filled, print it out. This
>>
>>> however isn't working how I planned. The following doesn't work.
>>
>>>
>>
>>> for fillempt in testdict:
>>
>>>      if fillempt == 'filled':
>>
>>>          print(testdict[fillempt])
>>
>>>
>>
>>> All this does though, is print glue, where I'd want it to print:
>>
>>>
>>
>>> apple
>>
>>> banana
>>
>>> eggs
>>
>>> glue
>>
>>>
>>
>>> Perhaps a dictionary isn't the best way to do this.. I wonder what else I
>>
>>> can do...
>>
>>
>>
>> A dictionary is spot-on, but you have to use the unique "apple",
>>
>> "banana",... as keys:
>>
>>
>>
>>>>> status = {"apple": "filled", "banana": "filled", "cake": "empty"}
>>
>>>>> for item in status:
>>
>> ...     if status[item] == "filled":
>>
>> ...             print(item)
>>
>> ...
>>
>> apple
>>
>> banana
>>
>>
>>
>> Could it be that you just confused dict keys with dict values?
>
> This fixed it, thank you! I did think a dictionary was right; I never considered swapping the keys with the values, though. A simple 'fix, but it worked. You've been a great help.
>

That's good to hear.

Would you please read and digest this 
https://wiki.python.org/moin/GoogleGroupsPython if you need to post 
again, a quick glance above will soon tell you why :)

-- 
Roses are red,
Violets are blue,
Most poems rhyme,
But this one doesn't.

Mark Lawrence




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