On Thursday, December 20, 2012 12:03:21 AM UTC+13, Steven D'Aprano wrote:
> On Wed, 19 Dec 2012 02:45:13 -0800, dgcosgrave wrote:
>
>
>
> > Hi Iam just starting out with python...My code below changes the txt
>
> > file into a list and add them to an empty dictionary and print how often
>
> > the word occurs, but it only seems to recognise and print the last entry
>
> > of the txt file. Any help would be great.
>
> >
>
> > tm =open('ask.txt', 'r')
>
> > dict = {}
>
> > for line in tm:
>
> > line = line.strip()
>
> > line = line.translate(None, '!"#$%&\'()*+,-./:;<=>?@[\\]^_`{|}~')
>
> > line = line.lower()
>
> > list = line.split(' ')
>
>
>
> Note: you should use descriptive names. Since this is a list of WORDS, a
>
> much better name would be "words" rather than list. Also, list is a built-
>
> in function, and you may run into trouble when you accidentally re-use
>
> that as a name. Same with using "dict" as you do.
>
>
>
> Apart from that, so far so good. For each line, you generate a list of
>
> words. But that's when it goes wrong, because you don't do anything with
>
> the list of words! The next block of code is *outside* the for-loop, so
>
> it only runs once the for-loop is done. So it only sees the last list of
>
> words.
>
>
>
> > for word in list:
>
>
>
> The problem here is that you lost the indentation. You need to indent the
>
> "for word in list" (better: "for word in words") so that it starts level
>
> with the line above it.
>
>
>
> > if word in dict:
>
> > count = dict[word]
>
> > count += 1
>
> > dict[word] = count
>
>
>
> This bit is fine.
>
>
>
> > else:
>
> > dict[word] = 1
>
>
>
> But this fails for the same reason! You have lost the indentation.
>
>
>
> A little-known fact: Python for-loops take an "else" block too! It's a
>
> badly named statement, but sometimes useful. You can write:
>
>
>
>
>
> for value in values:
>
> do_something_with(value)
>
> if condition:
>
> break # skip to the end of the for...else
>
> else:
>
> print "We never reached the break statement"
>
>
>
> So by pure accident, you lined up the "else" statement with the for loop,
>
> instead of what you needed:
>
>
>
> for line in tm:
>
> ... blah blah blah
>
> for word in words:
>
> if word in word_counts: # better name than "dict"
>
> ... blah blah blah
>
> else:
>
> ...
>
>
>
>
>
> > for word, count in dict.iteritems():
>
> > print word + ":" + str(count)
>
>
>
> And this bit is okay too.
>
>
>
>
>
> Good luck!
>
>
>
>
>
> --
>
> Steven
Thanks Steven appreciate great info for future coding. i have change names to
be more decriptive and corrected the indentation... all works! cheers
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