PyWb Component APIs

PyWb consists of several distinct subpackages, each of which may be useful on their own.

The following is an overview of the APIs expose by each package.

pywb.cdx

This package provides access to reading the cdx index from a variety of sources via a CDX server. The CDX Server supports the following api:

CDXServer.load_cdx(**params)

The params dictionary contains a parameters for the cdx query (currently a subset of CDX API listed here: https://github.com/internetarchive/wayback/tree/master/wayback-cdx-server)

The function returns an iterator of cdx objects, or plain text cdx stream. The cdx object is a dictionary containing available cdx fields.

pywb.warc

This package provides facilities for loading archived content from ARC and WARC files. First, It provides a low level api for loading one record at a time, given a full URI and an offset and length.

ArcWarcRecordLoader.load(self, uri, offset, length)

The URI must be a full local, file:// or http:// identifier. The load() functions returns a WARC/ARC record header header and a read stream to continue reading.

This package also provides a higher level API for interpreting a cdx line and returning the archived HTTP content.

resolvingloader.py provides the following interface:

ResolvingLoader.resolve_headers_and_payload(self, cdx, failed_files)

This function takes a cdx object from the cdx server (and an optional failed_files list to store failed attempts) and returns an http headers object + content stream pair, resolving any revisit records, as explained in PyWb-Record-Lookup-and-Revisits.

ResolvingLoader is initialized with an instance of CDXServer to allow for additional cdx lookups necessary for revisit lookup.

pywb.rewrite

The rewrite package deals with content rewriting necessary to replay archival content. It provides rewriters for HTML, CSS, JS, XML and http headers based on custom rules and a page specific url rewriter. The url rewriter is used to convert urls to be relative to a given archived page.

Currently, it provides the following main interface via rewrite_content.py

RewriteContent.rewrite_content(self, urlrewriter, headers, stream, head_insert_str = None):

The rewrite_content() function rewrites the http headers and consumes the input stream. An optional string to be inserted into the

for html content may be specified.

The function returns a pair of rewritten headers and an iterator of rewritten content. The headers and iterator are ready to be sent as part of a WSGI response.