what's the specification of python's heapq._siftdown() functionality?

I couldn't find a documentation about this function...

I specifically want to know what the parameters are and what 开发者_开发知识库do the parameters exactly represent...

using python 3

The convention in Python is to use a single leading _ for non-public methods and instance variables. So, _siftdown is not intended to be called externally and, thus, is not documented in the standard library documentation. If you want to examine how it works, look at the code. Note that the latest Python 3.2 documentation now includes links to the source code; see the link near the top of the page here.