[sametmax]

Really ? I though Python dicts and lists were actually quite fast for a dynamic language.

Ints and classes can be slow though.

Anything I don't know ?

[std_throwawayay]

They are probably the fastest dicts and lists we can imagine today. If you really need lists and dicts for your data, you need them and won't gain much. But if you don't need them and instead could use something simpler, an array of C structs would be much faster than a list of dicts.

[sametmax]

I though you were stating that Pythn were slow compared to what it could be, being a dynamic language.

Of course if you compare to static languages it's slow. Of course you can write low level specialized DS. Duh.