Sorting Driving Crazy: URGENT: PLEASE HELP

[xtian]

dont bother <dontbotherworld at yahoo.com> wrote in message news:<mailman.346.1079159911.19534.python-list at python.org>...
> This is really driving me crazy.
> 
> I have a dictionary feature_vectors{}. I try to sort
> its keys using
> 
> #apply sorting on feature_vectors
> sorted_feature_vector=feature_vectors.keys()
> sorted_feature_vector.sort()
> 
> #feature_vector.keys()=sorted_feature_vector
> 
> new_feature_element={}
> new_feature_vector={}
> 
> for x in sorted_feature_vector:
>     print "SORTING\n"
>     print x, '\t',feature_vectors[x]
>     count=0
>     if(count==0):
>         new_feature_element=str(1)+"
> "+str(x)+":"+str(feature_vectors[x])+" "
>     else:
>        
> new_feature_element=str(x)+":"+str(feature_vectors[x])+"
> "
>         count=count+1
>        
> new_feature_vector=str(new_feature_vector)+str(new_feature_element)
>         new_feature_vector=new_feature_vector+"\n"
>     
> print "New Dictionary"
> 
> 
> When I print x and feature_vectors[x]  I get some of
> the entries which are not in the increasing order.
> 
> 22836 	7.46464646465
> SORTING
> 
> 22840 	2.19977553311
> SORTING
> 
> 22841 	2.69809203143
> SORTING
> 
> 22842 	0.617283950617
> SORTING
> 
> 22844 	4.61279461279
> SORTING
> 
> 22846 	93.1537598204
> SORTING
> 
> 2357 	0.00224466891134
> SORTING
> 
> 3105 	0.00224466891134
> SORTING
> 
> 3117 	0.00224466891134
> SORTING
> 
> 3675 	0.003367003367
> SORTING
> 
> 4280 	0.00224466891134
> SORTING
> 

The keys of your feature_vectors dictionary are strings - they have
been sorted lexicographically. The string "22846" is less than the
string "2357".

To check this, you can put:

print "Type of x is", type(x)

into your loop. It will be <type 'str'>, while you want <type 'int'>.

To convert feature_vectors into a dictionary with integer keys, use
this:

new_feature_vectors = {}
for key, value in feature_vectors:
    new_feature_vectors[int(key)] = value

Then new_feature_vectors.keys() should be able to be sorted to have
the order you want.

On a side note, you seem to be having a lot of difficulty getting a
program to do what you want - have you worked through the tutorial
<http://www.python.org/doc/current/tut/tut.html>? The interactive
prompt can be very useful to check that snippets of code do what you
think they do.

Cheers,
xtian