how to keep order key in a dictionary

[azrael]

I 'm currenty working on a project for which it would be great to use
a dictionary. At the begining I have a list of strings that should
represent the keys in the dictionary. When I try to create a
dictionary it rearanges the keys. For this dictionary it is realy
important to keep the right order. Is it possible to arange them in a
specific order?

 

[Jeff McNeil]

See http://www.python.org/doc/faq/general/#how-are-dictionaries-implemented
.. In short, keys() and items() return an arbitrary ordering. I think
that http://pypi.python.org/pypi/Ordered Dictionary/ will do what
you want if key ordering is a necessity.

Jeff

 

[BartlebyScrivener]

For this dictionary it is realy
important to keep the right order. Is it possible to arange them in a
specific order?

Not sure what order you want, but how about sorting the keys?

def printdict(dict):
"""print sorted key:value pairs"""
keys = dict.keys()
keys.sort()
for key in keys:
print key, ":", dict[key]

from Python Visual Quickstart, Chris Fehily p. 157

 

[azrael]

thanks, the links where successfull

 

[Bruno Desthuilliers]

azrael a écrit :

I 'm currenty working on a project for which it would be great to use
a dictionary. At the begining I have a list of strings that should
represent the keys in the dictionary. When I try to create a
dictionary it rearanges the keys. For this dictionary it is realy
important to keep the right order. Is it possible to arange them in a
specific order?

No (not with the builtin dict type at least). You have to keep the order
by yourself. The nice thing is that you already have this : your list of
strings. Then you just have to iterate over this list and get to the dict:

for key in list_of_strings:
print dic[key]

HTH