itertools-package: The itertools Package

In itertools: Iterator Tools

Description

The itertools package provides a variety of functions used to create iterators, as defined by REvolution Computing's iterators package. Many of the functions are patterned after functions of the same name in the Python itertools module, including chain, product, izip, ifilter, etc. In addition, a number of functions were inspired by utility functions in the snow package, such as isplitRows, isplitCols, and isplitIndices.

There are also several utility functions that were contributed by Hadley Wickham that aid in writing iterators. These include is.iterator, end_iterator, iteration_has_ended, and new_iterator.

Details

More information is available on the following topics:

isplitVector	splits, or slices, a vector into shorter segments
isplitCols	splits a matrix column-wise
isplitRows	splits a matrix row-wise
isplitIndices	iterate over “chunks” of indices from 1 to n
chain	chain multiple iterators together into one iterator
enumerate	create an enumeration from an iterator
ichunk	create lists of values from an iterator to aid manual chunking
ihasNext	add a hasNext method to an iterator
ifilter	only return values for which a predicate function returns true
ifilterfalse	only return values for which a predicate function returns false
ilimit	limit, or truncate, an iterator
ireadBin	reads from a binary connection
irep	an iterator version of the rep function
irepeat	a simple repeating value iterator
izip	zip together multiple iterators
product	zip together multiple iterators in cartesian product fashion
recycle	recycle values from an iterator repeatedly
timeout	iterate for a specified number of seconds
is.iterator	indicates if an object is an iterator
end_iteration	throws an exception to signal end of iteration
iteration_has_ended	tests an exception to see if iteration has ended
new_iterator	creates a new iterator object

For a complete list of functions with individual help pages, use library(help="itertools").

itertools documentation built on May 2, 2019, 2:26 p.m.