SickGear/lib/html5lib/treewalkers/__init__.py

53 lines
2.4 KiB
Python
Raw Normal View History

"""A collection of modules for iterating through different kinds of
tree, generating tokens identical to those produced by the tokenizer
module.
To create a tree walker for a new type of tree, you need to do
implement a tree walker object (called TreeWalker by convention) that
implements a 'serialize' method taking a tree as sole argument and
returning an iterator generating tokens.
"""
treeWalkerCache = {}
def getTreeWalker(treeType, implementation=None, **kwargs):
"""Get a TreeWalker class for various types of tree with built-in support
treeType - the name of the tree type required (case-insensitive). Supported
values are "simpletree", "dom", "etree" and "beautifulsoup"
"simpletree" - a built-in DOM-ish tree type with support for some
more pythonic idioms.
"dom" - The xml.dom.minidom DOM implementation
"pulldom" - The xml.dom.pulldom event stream
"etree" - A generic walker for tree implementations exposing an
elementtree-like interface (known to work with
ElementTree, cElementTree and lxml.etree).
"lxml" - Optimized walker for lxml.etree
"beautifulsoup" - Beautiful soup (if installed)
"genshi" - a Genshi stream
implementation - (Currently applies to the "etree" tree type only). A module
implementing the tree type e.g. xml.etree.ElementTree or
cElementTree."""
treeType = treeType.lower()
if treeType not in treeWalkerCache:
if treeType in ("dom", "pulldom", "simpletree"):
mod = __import__(treeType, globals())
treeWalkerCache[treeType] = mod.TreeWalker
elif treeType == "genshi":
import genshistream
treeWalkerCache[treeType] = genshistream.TreeWalker
elif treeType == "beautifulsoup":
import soup
treeWalkerCache[treeType] = soup.TreeWalker
elif treeType == "lxml":
import lxmletree
treeWalkerCache[treeType] = lxmletree.TreeWalker
elif treeType == "etree":
import etree
# XXX: NEVER cache here, caching is done in the etree submodule
return etree.getETreeModule(implementation, **kwargs).TreeWalker
return treeWalkerCache.get(treeType)