def pprint(walker):
    """Pretty printer for tree walkers

    Takes a TreeWalker instance and pretty prints the output of walking the tree.

    :arg walker: a TreeWalker instance

    """
    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)
Pretty printer for tree walkers

    Takes a TreeWalker instance and pretty prints the output of walking the tree.

    :arg walker: a TreeWalker instance

    
product/gradle-plugin/src/main/python/pip/_vendor/html5lib/treewalkers/__init__.py