Next / Previous / Contents / TCC Help System / NM Tech homepage

Python 2.7 quick reference

20.36. `reversed()`: Produce a reverse iterator

This function, applied to a sequence S, returns an iterator that generates the elements of S in reverse order (see Section 24.2, “Iterators: Values that can produce a sequence of values”).

>>> L=[22,44,88]
>>> backL = reversed(L)
>>> for i in backL:
...     print i,
... 
88 44 22

The allowable values for S include all the types described in Section 8, “Sequence types”. It also works for any class provided one of these two conditions is met:

The method described in Section 26.3.20, “__reversed__(): Implement the reversed() function”.
If the class has no .__reversed__() method, reversed() will still work provided that instances act like a sequence; that is, the class has a .__len__() method and a .__getitem__() method.

Next: 20.37. round(): Round to the nearest integral value

Contents: Python 2.7 quick reference

Previous: 20.35. reduce(): Sequence reduction

Help: Tech Computer Center: Help System

Home: About New Mexico Tech

John W. Shipman

Comments welcome: tcc-doc@nmt.edu

Last updated: 2013-04-24 13:51

URL: http://www.nmt.edu