Re: Sort the values of a dict
Il Sat, 19 Dec 2009 17:30:27 +1100, Lie Ryan ha scritto:
On 12/19/2009 9:34 AM, mattia wrote:
Can you provide me a much pythonic solution (with comments if possible,
so I can actually learn something)?
If you only need to get i'th element sometimes, sorting the dict is
fine. Otherwise, you might want to use collections.OrderedDict.
Well, in the python doc OrderedDict is described as a dict that remembers
the order that keys were first inserted and I don't need this. The fact
is that I use a structure composed by a date and a list of possible
solutions found, like
(2009/12/21, (('e', 12, 33), ('r', 4, 11), ('r', 1, 33))) then every
solution is inserted concurrently in a dictionary. I want to sort the
solution found to provide, e.g., the first 10 dates found and the best
result of every date based on the i-th element of the date's list.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
mylist = [z for z in zip(list(d), list(d.values()))] The Pythonic way for the above line is: mylist = list(d.items()) Quite right. Thanks for pointing that out. I liked Chris Kaynor's solution: s = sorted(d.items(), key=lambda i: i[1][2]) I'm a bit rusty, and have just picked up the new Learning Python book but I'm finding that it isn't providing a useful refresher to the language or a particularly good introduction to version 3. Have you any suggestions. Regards Rory -- Rory Campbell-Lange r...@campbell-lange.net Campbell-Lange Workshop www.campbell-lange.net 0207 6311 555 3 Tottenham Street London W1T 2AF Registered in England No. 04551928 -- http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
Rory Campbell-Lange r...@campbell-lange.net writes: I'm a bit rusty, and have just picked up the new Learning Python book but I'm finding that it isn't providing a useful refresher to the language or a particularly good introduction to version 3. Have you any suggestions. While you aren't addressing me, I do have 2 suggestions: * Programming in Python 3 by Mark Summerfield (make sure you get the 2nd edition) * Dive into Python 3 by Mark Pilgrim I am halfway in the first book (but the 1st edition) and like it a lot. I know Dive into Python from an earlier version (2.x) and have no problem at all recommending the Python 3 edition. You can read/download it here: http://diveintopython3.org/ -- John Bokma Read my blog: http://johnbokma.com/ Hire me (Perl/Python): http://castleamber.com/ -- http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
On Fri, 18 Dec 2009 23:00:42 -, David Robinow drobi...@gmail.com
wrote:
I won't engage in any arguments about pythonicity but it seems simpler
if you convert to a list of tuples right away.
d = {1:('a', 1, 12), 5:('r',21,10), 2:('u',9,8)}
l = [(x, d[x]) for x in d.keys()]
which is a long way of writing l = d.items(), or l = list(d.items())
if you're using Python 3. :-)
def third(q):
return q[1][2]
s = sorted(l, key=third)
print s
--
Rhodri James *-* Wildebeeste Herder to the Masses
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
I'd write it as:
s = sorted(d.iteritems(), key=lambda i: i[1][2])
If using python 3, it should be d.items() instead of d.iteritems().
d.iteritems() is a generator yielding tuples of (key, value) from
the dictionary 'd'.
lambda i: i[1][2] is the same as:
def sort_(i):
return i[1][2]
but in-line.
Chris
On Fri, Dec 18, 2009 at 2:34 PM, mattia ger...@gmail.com wrote:
Hi all, I have a dictionary that uses dates and a tuples ad key, value
pairs. I need to sort the values of the dict and insert everything in a
tuple. The additional problem is that I need to sort the values looking
at the i-th element of the list. I'm not that good at python (v3.1), but
this is my solution:
d = {1:('a', 1, 12), 5:('r', 21, 10), 2:('u', 9, 8)}
t = [x for x in d.values()]
def third(mls):
... return mls[2]
...
s = sorted(t, key=third)
pres = []
for x in s:
... for k in d.keys():
... if d[k] == x:
... pres.append(k)
... break
...
res = []
for x in pres:
... res.append((x, d[x]))
...
res
[(2, ('u', 9, 8)), (5, ('r', 21, 10)), (1, ('a', 1, 12))]
Can you provide me a much pythonic solution (with comments if possible,
so I can actually learn something)?
Thanks, Mattia
--
http://mail.python.org/mailman/listinfo/python-list
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
Actually, in order to use duplicate values I need something like:
import copy
d = {1:('a', 1, 12), 5:('r', 21, 10), 2:('u', 9, 8), 3:('u', 9, 8) }
dc = copy.deepcopy(d)
t = [x for x in d.values()]
def third(mls):
... return mls[2]
...
s = sorted(t, key=third)
pres = []
for x in s:
... for k in d.keys():
... if d[k] == x:
... pres.append(k)
... del d[k] # speedup and use duplicate values
... break
...
res = []
for x in pres:
... res.append((x, dc[x]))
...
res
[(2, ('u', 9, 8)), (3, ('u', 9, 8)), (5, ('r', 21, 10)), (1, ('a', 1,
12))]
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
On Fri, Dec 18, 2009 at 5:34 PM, mattia ger...@gmail.com wrote:
Hi all, I have a dictionary that uses dates and a tuples ad key, value
pairs. I need to sort the values of the dict and insert everything in a
tuple. The additional problem is that I need to sort the values looking
at the i-th element of the list. I'm not that good at python (v3.1), but
this is my solution:
d = {1:('a', 1, 12), 5:('r', 21, 10), 2:('u', 9, 8)}
t = [x for x in d.values()]
def third(mls):
... return mls[2]
...
s = sorted(t, key=third)
pres = []
for x in s:
... for k in d.keys():
... if d[k] == x:
... pres.append(k)
... break
...
res = []
for x in pres:
... res.append((x, d[x]))
...
res
[(2, ('u', 9, 8)), (5, ('r', 21, 10)), (1, ('a', 1, 12))]
Can you provide me a much pythonic solution (with comments if possible,
so I can actually learn something)?
Thanks, Mattia
--
http://mail.python.org/mailman/listinfo/python-list
I won't engage in any arguments about pythonicity but it seems simpler
if you convert to a list of tuples right away.
d = {1:('a', 1, 12), 5:('r',21,10), 2:('u',9,8)}
l = [(x, d[x]) for x in d.keys()]
def third(q):
return q[1][2]
s = sorted(l, key=third)
print s
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
Il Fri, 18 Dec 2009 18:00:42 -0500, David Robinow ha scritto:
On Fri, Dec 18, 2009 at 5:34 PM, mattia ger...@gmail.com wrote:
Hi all, I have a dictionary that uses dates and a tuples ad key, value
pairs. I need to sort the values of the dict and insert everything in a
tuple. The additional problem is that I need to sort the values looking
at the i-th element of the list. I'm not that good at python (v3.1),
but this is my solution:
d = {1:('a', 1, 12), 5:('r', 21, 10), 2:('u', 9, 8)} t = [x for x in
d.values()]
def third(mls):
... return mls[2]
...
s = sorted(t, key=third)
pres = []
for x in s:
... for k in d.keys():
... if d[k] == x:
... pres.append(k)
... break
...
res = []
for x in pres:
... res.append((x, d[x]))
...
res
[(2, ('u', 9, 8)), (5, ('r', 21, 10)), (1, ('a', 1, 12))]
Can you provide me a much pythonic solution (with comments if possible,
so I can actually learn something)?
Thanks, Mattia
--
http://mail.python.org/mailman/listinfo/python-list
I won't engage in any arguments about pythonicity but it seems simpler
if you convert to a list of tuples right away.
d = {1:('a', 1, 12), 5:('r',21,10), 2:('u',9,8)} l = [(x, d[x]) for x in
d.keys()]
def third(q):
return q[1][2]
s = sorted(l, key=third)
print s
Thanks, I'm not yet aware of all the wonderful conversions python can do,
amazing.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
On 18/12/09, mattia (ger...@gmail.com) wrote:
Hi all, I have a dictionary that uses dates and a tuples ad key, value
pairs. I need to sort the values of the dict and insert everything in a
tuple. The additional problem is that I need to sort the values looking
at the i-th element of the list. I'm not that good at python (v3.1), but
this is my solution:
d = {1:('a', 1, 12), 5:('r', 21, 10), 2:('u', 9, 8)}
t = [x for x in d.values()]
def third(mls):
... return mls[2]
...
s = sorted(t, key=third)
pres = []
for x in s:
... for k in d.keys():
... if d[k] == x:
... pres.append(k)
... break
...
res = []
for x in pres:
... res.append((x, d[x]))
...
res
[(2, ('u', 9, 8)), (5, ('r', 21, 10)), (1, ('a', 1, 12))]
How about
mylist = [z for z in zip(list(d), list(d.values()))]
and then sort on your sort criteria, either i[0], i[0][1], i[0][2] or
i[0][3].
Rory
--
Rory Campbell-Lange
Director
r...@campbell-lange.net
Campbell-Lange Workshop
www.campbell-lange.net
0207 6311 555
3 Tottenham Street London W1T 2AF
Registered in England No. 04551928
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
Rory Campbell-Lange wrote:
On 18/12/09, mattia (ger...@gmail.com) wrote:
Hi all, I have a dictionary that uses dates and a tuples ad key, value
pairs. I need to sort the values of the dict and insert everything in a
tuple. The additional problem is that I need to sort the values looking
at the i-th element of the list. I'm not that good at python (v3.1), but
this is my solution:
d = {1:('a', 1, 12), 5:('r', 21, 10), 2:('u', 9, 8)}
t = [x for x in d.values()]
def third(mls):
... return mls[2]
...
s = sorted(t, key=third)
pres = []
for x in s:
... for k in d.keys():
... if d[k] == x:
... pres.append(k)
... break
...
res = []
for x in pres:
... res.append((x, d[x]))
...
res
[(2, ('u', 9, 8)), (5, ('r', 21, 10)), (1, ('a', 1, 12))]
How about
mylist = [z for z in zip(list(d), list(d.values()))]
The Pythonic way for the above line is:
mylist = list(d.items())
and then sort on your sort criteria, either i[0], i[0][1], i[0][2] or
i[0][3].
Rory
--
http://mail.python.org/mailman/listinfo/python-list
Re: Sort the values of a dict
On 12/19/2009 9:34 AM, mattia wrote: Can you provide me a much pythonic solution (with comments if possible, so I can actually learn something)? If you only need to get i'th element sometimes, sorting the dict is fine. Otherwise, you might want to use collections.OrderedDict. -- http://mail.python.org/mailman/listinfo/python-list
