Returns a safe copy if the value argument is mutable, otherwise returns the original argument. If the feedback keyword argument is True, then a tuple is returned containing the resulting argument, and whether or not is was mutable.

Translates text from using translate.google.com

Reads well formed RSS entries using standard python libraries

Quick way to get the users home directory in Unix/Linux and Windows

This class allows you to retrieve a companies current stock quote from Yahoo Finance, as well as current news feed entries for that company.

Introduction
This function is a function that returns a function. You pass it a function, and it returns a function that takes a collection as a parameter and applies your function to it. The difference between this and map is that this returns a function that you can use again which takes a collection as a parameter.

For Example
If I had a collection c, and a function p that prints its argument, I can create a visitor function using the following:
printVisitor=createVisitor(p)

Then any time I want to print a collection I just type:
printVisitor(c)

A Better Example
If you were writing an IRC server you would probably have many functions that operated on a list of users, such as ban,makeop, etc. You could create those functions in a manor similar to the following:

banUsers=createVisitor(ban)
makeOperators=createVisitor(makeop)

Then in a seperate file you could use these functions as if they were regular functions.

you would type banUsers(users) to ban, or makeOperators(users) to promote those users.

Very fast method for extracting all of the unique items from a list while preserving their original ordering.

Reads a file line by line using Python in 3 lines

Computes the difference between two dates in seconds

Decompress a .tar.bz2 archive in Pytho