What would be a nice way to go from {2:3, 1:89, 4:5, 3:0}
to {1:89, 2:3, 3:0, 4:5}
?
I checked some posts but they all use the "sorted" operator that returns tuples.
Standard Python dictionaries are unordered. Even if you sorted the (key,value) pairs, you wouldn't be able to store them in a dict
in a way that would preserve the ordering.
The easiest way is to use OrderedDict
, which remembers the order in which the elements have been inserted:
In [1]: import collections
In [2]: d = {2:3, 1:89, 4:5, 3:0}
In [3]: od = collections.OrderedDict(sorted(d.items()))
In [4]: od
Out[4]: OrderedDict([(1, 89), (2, 3), (3, 0), (4, 5)])
Never mind the way od
is printed out; it'll work as expected:
In [11]: od[1]
Out[11]: 89
In [12]: od[3]
Out[12]: 0
In [13]: for k, v in od.iteritems(): print k, v
....:
1 89
2 3
3 0
4 5
For Python 3 users, one needs to use the .items()
instead of .iteritems()
:
In [13]: for k, v in od.items(): print(k, v)
....:
1 89
2 3
3 0
4 5