Powerful and fast hash function in python (Search algorithm)

Question

Python has a default searching function which is:

x in [x,y,z,]

Where x,y,z can be any integers or characters, but this is a default sequential search and I want to know how I can use a manual hashing search in python.

"[x if x.getHashKeyMethod()==y.getHashKeyMethod() for x in myIterable]" will return all the objects with same hash as y from myIterable, is that it? — Ricola3D, Apr 19 '13 at 16:00

score 4 · Accepted Answer · answered Apr 19 '13 at 15:57

4

Use a set() instead:

x in {x,y,z}

This uses a hash table under the hood, so searches are O(1).

answered Apr 19 '13 at 15:57

Martijn Pieters

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hmmm, is this another built-in python function? – user1715095 Apr 19 '13 at 15:59
Yes, I linked you to the documentation for sets. Sets are a standard type. – Martijn Pieters Apr 19 '13 at 16:00
Whoa, I just learned about the `{1,2,3}` notation for sets. Has it always been there? I must have missed it... – David Zwicker Apr 19 '13 at 16:06
It is new in Python 2.7 and 3.x. – Martijn Pieters Apr 19 '13 at 16:14

Powerful and fast hash function in python (Search algorithm)

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