How to create an array which can be used also as a dictionary

Hans Müller heintest at web.de
Thu Sep 10 16:55:07 CEST 2009


Hello,

I have a lot of items having a name and a given sequence.

To access these items fast in a sequence order they should be used as 
a list, but to be fetched fast by name they also should be in a 
dictionary.

Code could be something like this.

class item
	def __init__(name, value1, value2, value3):
		self.name = name
		self.value1 = value1
		self.value2 = value2

a = []
a.append(item("foo", "bar", "text1"))
a.append(item("xyz", "basd", "tsddsfxt1"))
a.append(item("aax", "hello", "dont care"))

in a, i have my objects in given order, fast accessible by index, e.g. 
a[2] to get the third one. Fine.

Now I'd like to have a dict with references to thes objects like this:

d = {}
for x in a:
	d[a.name] = a	# do I get a copy of a here or a new reference ?!

In d i now have a dict, fast accessible by name.
But what happens if i modify
a[1].value1 = 1000
is
d["aax"].value1 now 1000 or still "hello" as in this example ?

Any ideas to get access to the SAME object by index (0..n-1) AND by key ?

Emphasis here is on speed.


Thanks a lot,

Hans



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