The Order Of Dictionary Entries

[Tim Daneliuk]

I am aware that dictionary order is not guaranteed. But I ran into
something puzzling today. I filled a dictionary dynamically as a
program ran. Up to a certain point, the key order was the order
in which things were added. However, at some point, the dictionary
appeared to reorder its contents in some non-deterministic way - in
fact, it looked like it was putting all the uppercase keys first,
followed by lowercase keys.

I'm just curious, just what _is_ the approach used for ordering
dictionary keys?

(This was confirmed on both Unix and Win32, BTW).
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Tim Daneliuk tu****@tundraware.com
PGP Key: http://www.tundraware.com/PGP/

[Aahz]

In article <in*************@eskimo.tundraware.com>,
Tim Daneliuk <tu****@tundraware.com> wrote:

I am aware that dictionary order is not guaranteed. But I ran into
something puzzling today. I filled a dictionary dynamically as a
program ran. Up to a certain point, the key order was the order
in which things were added. However, at some point, the dictionary
appeared to reorder its contents in some non-deterministic way - in
fact, it looked like it was putting all the uppercase keys first,
followed by lowercase keys.

I'm just curious, just what _is_ the approach used for ordering
dictionary keys?

Use the source, Luke. See Objects/dictobject.c

Hint: dicts are based on hashing.
--
Aahz (aa**@pythoncraft.com) <*> http://www.pythoncraft.com/

"Do not taunt happy fun for loops. Do not change lists you are looping over."
--Remco Gerlich, comp.lang.python

[Terry Reedy]

"Tim Daneliuk" <tu****@tundraware.com> wrote in message
news:in*************@eskimo.tundraware.com...

I am aware that dictionary order is not guaranteed. But I ran into
something puzzling today. I filled a dictionary dynamically as a
program ran. Up to a certain point, the key order was the order
in which things were added.

I am rather certain that this was an accident dependent on you adding the
keys in the order in which they were going to displayed. Try adding the
items in a different order and the display order should not change much if
at all. Example:

{1:1, 2:2} {1: 1, 2: 2} {2:2, 1:1}

{1: 1, 2: 2}

Terry J. Reedy