[Tutor] simple list query

[Dave S]

Patrick Hall wrote:

>Hi Dave,
>
>  
>
>>I have a list consisting of about 250 items, I need to know if a
>>particular item is in the list. I know this is better suited to  a
>>dictionary but thats not the way it ended up ;-)
>>    
>>
>
>  
>
>>I could do a for loop to scan the list & compare each one, but I have a
>>suspission that there is a better way ?
>>    
>>
>
>Indeed there is: just use the built-in "in":
>
>  
>
>>>>li = ['a', 'b', 'c', 'd', 'e', 'f', 'a', 'b', 'c']
>>>>'a' in li
>>>>        
>>>>
>True
>  
>
>>>>'z' in li
>>>>        
>>>>
>False
>
>That's a small example, but it will work equally well with a long
>list. For instance, we can check to see if the words "Ahab", "whale",
>and "pizza" are in the text of "Moby Dick" (I have the text in a file
>called "moby.txt".)
>
>  
>
>>>>moby = open('moby.txt').read() # Moby Dick, the whole thing!
>>>>mobywords = moby.split() # now mobywords has all the words in the text
>>>>'Ahab' in mobywords
>>>>        
>>>>
>True
>  
>
>>>>'whale' in mobywords
>>>>        
>>>>
>True
>  
>
>>>>'pizza' in mobywords
>>>>        
>>>>
>False
>
>These results are unsurprising. 8^)
>
>A list of 250 words is no problem -- "Moby Dick" has a couple hundred thousand:
>
>  
>
>>>>len(mobywords)
>>>>        
>>>>
>214112
>
>I'm not sure I understand why you think a dictionary would be better
>in this case, a list seems fine to me.
>
>Best,
>Pat
>_______________________________________________
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>
>  
>
Thanks guys, something was rattling round by brain that there was a way, 
but I just could not work it out :-)

Dave