[Tutor] Having trouble with a dictionary of lists

[Emile van Sebille]

On 9/4/2009 9:09 AM William Witteman said...
> On Thu, Sep 03, 2009 at 11:26:35AM -0700, Emile van Sebille wrote:
> 
> Thanks to Emile for pointing out the error.  There were several other
> errors - initiating the counter in the loop (d'oh!), premature sorting
> of the dictionary by keys, not providing an index row for the output
> file, not returning anything from my function, and probably others.
> 
> Here is how it looks now - any pointers, stylistic or otherwise, are
> welcome.  It does, however, work.

That's normally when I stop looking at it.  If I'm lucky, I'll never 
need to work on it again.  If and when I do, that's when I clean it up 
in the area that needs attention.  It's way to easy IMHO to turn one-off 
projects into time-sinks.

Anyway, some notes interspersed below...

Emile


> 
> #!/usr/bin/python
> 
> """
> Take a collection of lists, combine them into one list, deleting duplicates.
> Sort the list and use it as the leftmost column of a table.  Then put each 
> lists contents into the table, one per column, with the elements aligned
> with the leftmost (index) column.
> 
> """
> 
> import os, sys, csv
> 
> def cmpss(filename,*sslists):
>   """Write a CSV file from the collection of lists."""
> 
>   if os.path.exists(filename):
>     print("%s exists: please choose another filename." % filename)
>     sys.exit(1)
>   else:
>     try:
>       fn = csv.writer(open(filename, "w"))
>     except IOError:
>       print("There is a problem opening the requested file.  Sorry.")
>       sys.exit(1)
>   toprow = [x for x in range(len(sslists))]

This looks like toprow is simply range(len(sslists))...

>   toprow.insert(0, "index")
>   fn.writerow(toprow)
> 
>   termdict = {}
>   number_of_columns = len(sslists)
> 
>   for sslist in sslists:
>     for term in sslist:
>       termdict[term] = ["" for x in range(number_of_columns)]

this might also be said  [""]*number_of_columns

>   
>   sortedtermlist = termdict.keys()
>   sortedtermlist.sort()
> 
>   counter = 0
>   
>   for sslist in sslists:
>     for term in sslist:
>       #debug print(counter)
>       #debug print(term)
>       termdict[term][counter] = term
>     counter = counter + 1
> 
>   for term in sortedtermlist:
>     row = [term]
>     row.extend(termdict[term])
>     fn.writerow(row)
> 
>   return termdict
> 
>