Re: converting a set into a sorted list

[MackS]

Thank you for the pointer. I'll upgrade to 2.4.

Best,

Mack

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Re: converting a set into a sorted list

[Bengt Richter]

On Sat, 14 May 2005 19:20:24 -0700, Robert Kern [EMAIL PROTECTED] wrote:

MackS wrote:
 Dear all,
 
 I've got several large sets in my program. After performing several
 operations on these I wish to present one set to the user [as a list]
 sorted according to a certain criterion. Is there any direct way to do
 so? Or must I
 
 list = []
 
 for item in set1:
list.append(item)
 
 list.sort()
 
 Can I somehow avoid doing this in two stages? Can I somehow avoid first
 creating a long list only to immediately sort it afterwards?

In Python 2.4,

In [1]:sorted?
Type:   builtin_function_or_method
Base Class: type 'builtin_function_or_method'
String Form:built-in function sorted
Namespace:  Python builtin
Docstring:
 sorted(iterable, cmp=None, key=None, reverse=False) -- new sorted list

That's plenty of information, but IMO key=None doesn't hint strongly enough
about what you can do with it, so I'd advise reading about all the parameters 
;-)

Regards,
Bengt Richter
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converting a set into a sorted list

[MackS]

Dear all,

I've got several large sets in my program. After performing several
operations on these I wish to present one set to the user [as a list]
sorted according to a certain criterion. Is there any direct way to do
so? Or must I

list = []

for item in set1:
   list.append(item)

list.sort()

Can I somehow avoid doing this in two stages? Can I somehow avoid first
creating a long list only to immediately sort it afterwards?

Thanks for any guidance,

Mack

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Re: converting a set into a sorted list

[Robert Kern]

MackS wrote:
 Dear all,
 
 I've got several large sets in my program. After performing several
 operations on these I wish to present one set to the user [as a list]
 sorted according to a certain criterion. Is there any direct way to do
 so? Or must I
 
 list = []
 
 for item in set1:
list.append(item)
 
 list.sort()
 
 Can I somehow avoid doing this in two stages? Can I somehow avoid first
 creating a long list only to immediately sort it afterwards?

In Python 2.4,

In [1]:sorted?
Type:   builtin_function_or_method
Base Class: type 'builtin_function_or_method'
String Form:built-in function sorted
Namespace:  Python builtin
Docstring:
 sorted(iterable, cmp=None, key=None, reverse=False) -- new sorted list

-- 
Robert Kern
[EMAIL PROTECTED]

In the fields of hell where the grass grows high
  Are the graves of dreams allowed to die.
   -- Richard Harter

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Re: converting a set into a sorted list

[Terry Reedy]

MackS [EMAIL PROTECTED] wrote in message 
news:[EMAIL PROTECTED]
 Can I somehow avoid doing this in two stages? Can I somehow avoid first
 creating a long list only to immediately sort it afterwards?

Yes, you could interatively extract and append the min of the set 
(selection sort), but this would be O(n**2), like bubble or insert sort, 
instead of the O(n*logn) of make list and sort.  You can do the latter in 
two statements without append:
 display = list(big_set)
 display.sort().

As Robert noted, this can be condensed to one using sorted, but that will 
do the same as the two lines above.

Terry J. Reedy



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Re: converting a set into a sorted list

[Brian Beck]

Robert Kern wrote:
 MackS wrote:
 
 Dear all,

 I've got several large sets in my program. After performing several
 operations on these I wish to present one set to the user [as a list]
 sorted according to a certain criterion. Is there any direct way to do
 so? Or must I

 list = []

 for item in set1:
list.append(item)

 list.sort()

So, for this example, just do:

sorted(set1)


-- 
Brian Beck
Adventurer of the First Order
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