AlkantarClanX12
Current Path : /proc/self/root/usr/lib/python2.7/site-packages/pip/_vendor/html5lib/treewalkers/ |
Current File : //proc/self/root/usr/lib/python2.7/site-packages/pip/_vendor/html5lib/treewalkers/__init__.py |
"""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. """ from __future__ import absolute_import, division, unicode_literals from .. import constants from .._utils import default_etree __all__ = ["getTreeWalker", "pprint", "dom", "etree", "genshi", "etree_lxml"] treeWalkerCache = {} def getTreeWalker(treeType, implementation=None, **kwargs): """Get a TreeWalker class for various types of tree with built-in support Args: treeType (str): the name of the tree type required (case-insensitive). Supported values are: - "dom": The xml.dom.minidom DOM implementation - "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 - "genshi": a Genshi stream Implementation: A module implementing the tree type e.g. xml.etree.ElementTree or cElementTree (Currently applies to the "etree" tree type only). """ treeType = treeType.lower() if treeType not in treeWalkerCache: if treeType == "dom": from . import dom treeWalkerCache[treeType] = dom.TreeWalker elif treeType == "genshi": from . import genshi treeWalkerCache[treeType] = genshi.TreeWalker elif treeType == "lxml": from . import etree_lxml treeWalkerCache[treeType] = etree_lxml.TreeWalker elif treeType == "etree": from . import etree if implementation is None: implementation = default_etree # XXX: NEVER cache here, caching is done in the etree submodule return etree.getETreeModule(implementation, **kwargs).TreeWalker return treeWalkerCache.get(treeType) def concatenateCharacterTokens(tokens): pendingCharacters = [] for token in tokens: type = token["type"] if type in ("Characters", "SpaceCharacters"): pendingCharacters.append(token["data"]) else: if pendingCharacters: yield {"type": "Characters", "data": "".join(pendingCharacters)} pendingCharacters = [] yield token if pendingCharacters: yield {"type": "Characters", "data": "".join(pendingCharacters)} def pprint(walker): """Pretty printer for tree walkers""" output = [] indent = 0 for token in concatenateCharacterTokens(walker): type = token["type"] if type in ("StartTag", "EmptyTag"): # tag name if token["namespace"] and token["namespace"] != constants.namespaces["html"]: if token["namespace"] in constants.prefixes: ns = constants.prefixes[token["namespace"]] else: ns = token["namespace"] name = "%s %s" % (ns, token["name"]) else: name = token["name"] output.append("%s<%s>" % (" " * indent, name)) indent += 2 # attributes (sorted for consistent ordering) attrs = token["data"] for (namespace, localname), value in sorted(attrs.items()): if namespace: if namespace in constants.prefixes: ns = constants.prefixes[namespace] else: ns = namespace name = "%s %s" % (ns, localname) else: name = localname output.append("%s%s=\"%s\"" % (" " * indent, name, value)) # self-closing if type == "EmptyTag": indent -= 2 elif type == "EndTag": indent -= 2 elif type == "Comment": output.append("%s<!-- %s -->" % (" " * indent, token["data"])) elif type == "Doctype": if token["name"]: if token["publicId"]: output.append("""%s<!DOCTYPE %s "%s" "%s">""" % (" " * indent, token["name"], token["publicId"], token["systemId"] if token["systemId"] else "")) elif token["systemId"]: output.append("""%s<!DOCTYPE %s "" "%s">""" % (" " * indent, token["name"], token["systemId"])) else: output.append("%s<!DOCTYPE %s>" % (" " * indent, token["name"])) else: output.append("%s<!DOCTYPE >" % (" " * indent,)) elif type == "Characters": output.append("%s\"%s\"" % (" " * indent, token["data"])) elif type == "SpaceCharacters": assert False, "concatenateCharacterTokens should have got rid of all Space tokens" else: raise ValueError("Unknown token type, %s" % type) return "\n".join(output)