rename keys in a dictionary

Question

i want to rename the keys of a dictionary are which are ints, and i need them to be ints with leading zeros's so that they sort correctly.

for example my keys are like:

'1','101','11'

and i need them to be:

'001','101','011'

this is what im doing now, but i know there is a better way

tmpDict = {}
  for oldKey in aDict:
 tmpDict['%04d'%int(oldKey)] = aDict[oldKey]
newDict = tmpDict

Im confused. Why doesn't a numerical sort work to sort the keys? Dictionaries guarantee no sort order for keys so changing the key. — Alan, Jun 14 '10 at 20:38
Why not convert them to numbers? ( you can even display them as binary if needed) — mmmmmm, Jun 14 '10 at 20:41

score 7 · Accepted Answer · answered Jun 14 '10 at 20:52

7

You're going about it the wrong way. If you want to pull the entries from the dict in a sorted manner then you need to sort upon extraction.

for k in sorted(D, key=int):
  print '%s: %r' % (k, D[k])

answered Jun 14 '10 at 20:52

score 1 · Answer 2 · answered Jun 14 '10 at 20:52

1

You can sort with whatever key you want.

So, for example: sorted(mydict, key=int)

answered Jun 14 '10 at 20:52

Tamás · Answer 3 · 2010-06-14T20:45:07.967

0

aDict = dict((('%04d' % oldKey, oldValue) \
             for (oldKey, oldValue) in aDict.iteritems()))

...or %03d if you need three digits as in your example.

edited Jun 14 '10 at 20:45

answered Jun 14 '10 at 20:37

Tamás

3 Answers3