I've been spending today learning python and as an exercise I've ported a program I wrote in java that unscrambles a word. Before describing the problem, here's the code:
*--beginning of file--* #!/usr/bin/python # Filename: unscram.py
def sort_string(word): '''Returns word in lowercase sorted alphabetically''' word = str.lower(word) word_list = [] for char in word: word_list.append(char) word_list.sort() sorted_word = '' for char in word_list: sorted_word += char return sorted_word
print 'Building dictionary...',
dictionary = { }
# Notice that you need to have a file named 'dictionary.txt' # in the same directory as this file. The format is to have # one word per line, such as the following (of course without # the # marks):
#test #hello #quit #night #pear #pare
f = file('dictionary.txt')
# This loop builds the dictionary, where the key is # the string after calling sort_string(), and the value # is the list of all 'regular' words (from the dictionary, # not sorted) that passing to sort_string() returns the key
while True: line = f.readline() if len(line) == 0: break line = str.lower(line[:-1]) # convert to lowercase just in case and # remove the return at the end of the line sline = sort_string(line) if sline in dictionary: # this key already exist, add to existing list dictionary[sline].append(line) print 'Added %s to key %s' % (line,sline) #for testing else: # create new key and list dictionary[sline] = [line] print 'Created key %s for %s' % (sline,line) #for testing f.close()
print 'Ready!'
# This loop lets the user input a scrambled word, look for it in # dictionary, and print all matching unscrambled words. # If the user types 'quit' then the program ends. while True: lookup = raw_input('Enter a scrambled word : ')
results = dictionary[sort_string(lookup)]
for x in results: print x,
print
if lookup == 'quit': break *--end of file--*
If you create dictionary.txt as suggested in the comments, it should work fine (assumeing you pass a word that creates a valid key, I'll have to add exceptions later). The problem is when using a large dictionary.txt file (2.9 MB is the size of the dictionary I tested) it always gives an error, specifically: (Note: ccehimnostyz is for zymotechnics, which is in the large dictionary)
*--beginning of example--* Enter a scrambled word : ccehimnostyz Traceback (most recent call last): File "unscram.py", line 62, in ? results = dictionary[sort_string(lookup)] KeyError: 'ccehimnostyz' *--end of example--*
If you'd like a copy of the dictionary I'm using email me at teoryn at gmail dot com or leave your email here and I'll send it to you (It's 702.2 KB compressed)
teoryn wrote: > I've been spending today learning python and as an exercise I've ported > a program I wrote in java that unscrambles a word. Before describing > the problem, here's the code:
> *--beginning of file--* > #!/usr/bin/python > # Filename: unscram.py
> def sort_string(word): > '''Returns word in lowercase sorted alphabetically''' > word = str.lower(word) > word_list = [] > for char in word: > word_list.append(char) > word_list.sort() > sorted_word = '' > for char in word_list: > sorted_word += char > return sorted_word
> print 'Building dictionary...',
> dictionary = { }
> # Notice that you need to have a file named 'dictionary.txt' > # in the same directory as this file. The format is to have > # one word per line, such as the following (of course without > # the # marks):
> #test > #hello > #quit > #night > #pear > #pare
> f = file('dictionary.txt')
> # This loop builds the dictionary, where the key is > # the string after calling sort_string(), and the value > # is the list of all 'regular' words (from the dictionary, > # not sorted) that passing to sort_string() returns the key
> while True: > line = f.readline() > if len(line) == 0: > break > line = str.lower(line[:-1]) # convert to lowercase just in case > and > # remove the return at the end of > the line > sline = sort_string(line) > if sline in dictionary: # this key already exist, add to > existing list > dictionary[sline].append(line) > print 'Added %s to key %s' % (line,sline) #for testing > else: # create new key and list > dictionary[sline] = [line] > print 'Created key %s for %s' % (sline,line) #for > testing > f.close()
> print 'Ready!'
> # This loop lets the user input a scrambled word, look for it in > # dictionary, and print all matching unscrambled words. > # If the user types 'quit' then the program ends. > while True: > lookup = raw_input('Enter a scrambled word : ')
> results = dictionary[sort_string(lookup)]
> for x in results: > print x,
> print
> if lookup == 'quit': > break > *--end of file--*
> If you create dictionary.txt as suggested in the comments, it should > work fine (assumeing you pass a word that creates a valid key, I'll > have to add exceptions later). The problem is when using a large > dictionary.txt file (2.9 MB is the size of the dictionary I tested) it > always gives an error, specifically: > (Note: ccehimnostyz is for zymotechnics, which is in the large > dictionary)
> *--beginning of example--* > Enter a scrambled word : ccehimnostyz > Traceback (most recent call last): > File "unscram.py", line 62, in ? > results = dictionary[sort_string(lookup)] > KeyError: 'ccehimnostyz' > *--end of example--*
> If you'd like a copy of the dictionary I'm using email me at teoryn at > gmail dot com or leave your email here and I'll send it to you (It's > 702.2 KB compressed)
> Thanks, > Kevin
Heh, it reminds me of the code I used to write.
def sort_string(word): return ''.join(sorted(list(word.lower()))) f = open('dictionary.txt','r') lines = [line.rstrip('\n') for line in f.readlines()] f.close() dictionary = dict((sort_string(line),line) for line in lines) lookup = '' while lookup != 'quit': lookup = raw_input('Enter a scrambled word:') if dictionary.has_key(lookup): word = dictionary[lookup] else: word = 'Not found.' print word
Devan L wrote: > Heh, it reminds me of the code I used to write.
> def sort_string(word): > return ''.join(sorted(list(word.lower()))) > f = open('dictionary.txt','r') > lines = [line.rstrip('\n') for line in f.readlines()] > f.close() > dictionary = dict((sort_string(line),line) for line in lines)
That's definitely not the kind of dictionary that he wants.
Kevin, I'm pretty new to Python too. I'm not sure why you're seeing this problem... is it possible that this is an "out-by-one" error? Is zymotechnics the *last* word in dictionary.txt? Try this slightly simplified version of your program and see if you have the same problem....
def sort_string(word): '''Returns word in lowercase sorted alphabetically''' return "".join(sorted(list(word.lower())))
dictionary = {} f = open('/usr/bin/words') # or whatever file you like for line in f: sline = sort_string(line[:-1]) if sline in dictionary: dictionary[sline].append(line) else: dictionary[sline] = [line] f.close()
lookup = raw_input('Enter a scrambled word : ') while lookup: try: results = dictionary[sort_string(lookup)] for x in results: print x, print except: print "?????" lookup = raw_input('Enter a scrambled word : ')
teoryn wrote: > I've been spending today learning python and as an exercise I've ported > a program I wrote in java that unscrambles a word. Before describing > the problem, here's the code:
> *--beginning of file--* > #!/usr/bin/python > # Filename: unscram.py
> def sort_string(word): > '''Returns word in lowercase sorted alphabetically''' > word = str.lower(word) > word_list = [] > for char in word: > word_list.append(char) > word_list.sort() > sorted_word = '' > for char in word_list: > sorted_word += char > return sorted_word
An idiomatic Python 2.4 version of this function would be:
> # Notice that you need to have a file named 'dictionary.txt' > # in the same directory as this file. The format is to have > # one word per line, such as the following (of course without > # the # marks):
> #test > #hello > #quit > #night > #pear > #pare
> f = file('dictionary.txt')
> # This loop builds the dictionary, where the key is > # the string after calling sort_string(), and the value > # is the list of all 'regular' words (from the dictionary, > # not sorted) that passing to sort_string() returns the key
> while True: > line = f.readline() > if len(line) == 0: > break > line = str.lower(line[:-1]) # convert to lowercase just in case > and > # remove the return at the end of > the line > sline = sort_string(line) > if sline in dictionary: # this key already exist, add to > existing list > dictionary[sline].append(line) > print 'Added %s to key %s' % (line,sline) #for testing > else: # create new key and list > dictionary[sline] = [line] > print 'Created key %s for %s' % (sline,line) #for > testing > f.close()
# this really should all be within a function, but let's just carry on dictionary = {} f = open('dictionary.txt') try: # enclose this in a try: finally: block in case something goes wrong for line in f: line = line.strip().lower() sline = sort_string(line) val = dictionary.setdefault(sline, []) val.append(line) print "Added %s to key %s" % (line, sline) finally: f.close()
> # This loop lets the user input a scrambled word, look for it in > # dictionary, and print all matching unscrambled words. > # If the user types 'quit' then the program ends. > while True: > lookup = raw_input('Enter a scrambled word : ')
> results = dictionary[sort_string(lookup)]
> for x in results: > print x,
> print
> if lookup == 'quit': > break > *--end of file--*
> If you create dictionary.txt as suggested in the comments, it should > work fine (assumeing you pass a word that creates a valid key, I'll > have to add exceptions later). The problem is when using a large > dictionary.txt file (2.9 MB is the size of the dictionary I tested) it > always gives an error, specifically: > (Note: ccehimnostyz is for zymotechnics, which is in the large > dictionary)
Well, my version works (using /usr/share/dict/words from Debian as dictionary.txt). Yours does, too. Are you sure that you are using the right dictionary.txt?
teoryn wrote: > I've been spending today learning python and as an exercise I've ported > a program I wrote in java that unscrambles a word. Before describing > the problem, here's the code: > line = str.lower(line[:-1]) # convert to lowercase just in case > have to add exceptions later). The problem is when using a large > dictionary.txt file (2.9 MB is the size of the dictionary I tested) it > always gives an error, specifically: > (Note: ccehimnostyz is for zymotechnics, which is in the large > dictionary)
> *--beginning of example--* > Enter a scrambled word : ccehimnostyz > Traceback (most recent call last): > File "unscram.py", line 62, in ? > results = dictionary[sort_string(lookup)] > KeyError: 'ccehimnostyz' > *--end of example--*
If 'zymotechnics' is the last line and that line is missing a trailing newline
line[:-1]
mutilates 'zymotechnics' to 'zymotechnic'. In that case the dictionary would contain the key 'ccehimnotyz'. Another potential problem could be leading/trailing whitespace. Both problems can be fixed by using line.strip() instead of line[:-1] as in Robert Kern's code.
On Sun, 24 Jul 2005 20:44:08 -0700, teoryn wrote: > I've been spending today learning python and as an exercise I've ported > a program I wrote in java that unscrambles a word. Before describing > the problem, here's the code:
> *--beginning of file--* > #!/usr/bin/python > # Filename: unscram.py
> def sort_string(word): > '''Returns word in lowercase sorted alphabetically''' > word = str.lower(word)
It is generally considered better form to write that line as:
word = word.lower()
> word_list = [] > for char in word: > word_list.append(char)
If you want a list of characters, the best way of doing that is just:
word_list = list(word)
> word_list.sort() > sorted_word = '' > for char in word_list: > sorted_word += char > return sorted_word
> # Notice that you need to have a file named 'dictionary.txt' > # in the same directory as this file. The format is to have > # one word per line, such as the following (of course without > # the # marks):
> #test > #hello > #quit > #night > #pear > #pare
> f = file('dictionary.txt')
> # This loop builds the dictionary, where the key is > # the string after calling sort_string(), and the value > # is the list of all 'regular' words (from the dictionary, > # not sorted) that passing to sort_string() returns the key
> while True: > line = f.readline() > if len(line) == 0: > break > line = str.lower(line[:-1]) # convert to lowercase just in case > and > # remove the return at the end of > the line > sline = sort_string(line) > if sline in dictionary: # this key already exist, add to > existing list > dictionary[sline].append(line) > print 'Added %s to key %s' % (line,sline) #for testing > else: # create new key and list > dictionary[sline] = [line] > print 'Created key %s for %s' % (sline,line) #for > testing > f.close()
Your while-loop seems to have been mangled a little thanks to word-wrap. In particular, I can't work out what that "and" is doing in the middle of it.
Unless you are expecting really HUGE dictionary files (hundreds of millions of lines) perhaps a better way of writing the above while-loop would be:
print 'Building dictionary...', dictionary = { } f = file('dictionary.txt', 'r') for line in f.readlines() line = line.strip() # remove whitespace at both ends if line: # line is not the empty string line = line.lower() sline = sort_string(line) if sline in dictionary: dictionary[sline].append(line) print 'Added %s to key %s' % (line,sline) else: dictionary[sline] = [line] print 'Created key %s for %s' % (sline,line) f.close()
> print 'Ready!'
> # This loop lets the user input a scrambled word, look for it in > # dictionary, and print all matching unscrambled words. > # If the user types 'quit' then the program ends. > while True: > lookup = raw_input('Enter a scrambled word : ')
> results = dictionary[sort_string(lookup)]
This will fail if the scrambled word you enter is not in the dictionary.
> for x in results: > print x,
> print
> if lookup == 'quit': > break
You probably want the test for quit to happen before printing the "unscrambled" words.
> If you create dictionary.txt as suggested in the comments, it should > work fine (assumeing you pass a word that creates a valid key, I'll > have to add exceptions later). The problem is when using a large > dictionary.txt file (2.9 MB is the size of the dictionary I tested) it > always gives an error, specifically: > (Note: ccehimnostyz is for zymotechnics, which is in the > large dictionary)
> *--beginning of example--* > Enter a scrambled word : ccehimnostyz Traceback (most recent call last): > File "unscram.py", line 62, in ? > results = dictionary[sort_string(lookup)] > KeyError: 'ccehimnostyz' > *--end of example--*
If this error is always happening for the LAST line in the text file, I'm guessing there is no newline after the word. So when you read the text file and build the dictionary, you inadvertently remove the "s" from the word before storing it in the dictionary.
Here's the (at least for now) final script, although note I'm using 2.3.5, not 2.4, so I can't use some of the tips that were given.
#!/usr/bin/python # Filename: unscram.py
def sort_string(word): '''Returns word in lowercase sorted alphabetically''' word_list = list(word.lower()) word_list.sort() return ''.join(word_list)
print 'Building dictionary...',
dictionary = { }
f = file('/usr/share/dict/words', 'r')
for line in f.readlines(): line = line.strip() # remove whitespace at both ends if line: # line is not the empty string line = line.lower() sline = sort_string(line) if sline in dictionary: dictionary[sline].append(line) #print 'Added %s to key %s' % (line,sline) else: dictionary[sline] = [line] #print 'Created key %s for %s' % (sline,line) f.close()
print 'Ready!'
lookup = raw_input('Enter a scrambled word : ') while lookup: try: results = dictionary[sort_string(lookup)] for x in results: print x, print except: print "?????" lookup = raw_input('Enter a scrambled word : ')
As for the end of the file idea, that word wasn't at the end of the file, and there was a blank line, so that's out of the question. The word list I was using was 272,520 words long, and I got it a while back when doing this same thing in java, but as you can see now I'm just using /usr/share/dict/words which I found after not finding it in the place listed in Nick's comment.
I'm still lost as to why my old code would only work for the small file, and another interesting note is that with the larger file, it would only write "zzz for zzz" (or whatever each word was) instead of "Created key zzz for zzz". However, it works now, so I'm happy.
teoryn wrote: > I'm still lost as to why my old code would only work for the small > file, and another interesting note is that with the larger file, it > would only write "zzz for zzz" (or whatever each word was) instead of > "Created key zzz for zzz". However, it works now, so I'm happy.
Happy as long as you don't know what happened? How can that be? Another guess then -- there may be inconsistent newlines, some "\n" and some "\r\n":
teoryn wrote: > I changed to using line = line.strip() instead of line = line [:-1] in > the original and it it worked.
Just to be clear, these don't do nearly the same thing in general, though in your specific case they might appear similar.
The line[:-1] idiom says 'return a string which is a copy of the original but with the last character, if any, removed, regardless of what character it is'.
The line.strip() idiom says 'return a string with all whitespace characters removed from the end *and* start of the string'.
In certain cases, you might reasonably prefer .rstrip() (which removes only from the right-hand side, or end), or even something like .rstrip('\n') which would remove only newlines from the end.
