efficiency question

[David Harvey]

Hi,

Suppose I write

	if x in ("abc", "def", "xyz"):
		doStuff()

	elif x in ("pqr", "tuv", "123"):
		doOtherStuff()

	elif ...

etc.

When is python building the tuples? Does it need to build the tuple  
every time it comes through this code? Or does it somehow recognise  
that they are constant and cache them?

In other words, is anything gained (efficiency-wise) by first putting  
say

	tuple1 = ("abc", "def", "xyz")
	tuple2 = ("pqr", "tuv", "123")

somewhere where I know it's executed once, and then writing

	if x in tuple1:
		doStuff()

	elif x in tuple2:
		doOtherStuff()

	elif ...

????

(The tuples I have in mind are of course much longer than three  
elements)

Many thanks

David