Module etree

Element factory. This function returns an object implementing the Element interface.

Also look at the _Element.makeelement() and _BaseParser.makeelement() methods, which provide a faster way to create an Element within a specific document or parser context.

Build a dictionary of extension functions from the functions defined in a module or the methods of an object.

As second argument, you can pass an additional mapping of attribute names to XPath function names, or a list of function names that should be taken.

The ns keyword argument accepts a namespace URI for the XPath functions.

Retrieve the function namespace object associated with the given URI.

Creates a new one if it does not yet exist. A function namespace can only be used to register extension functions.

Usage:

>>> ns_functions = FunctionNamespace("http://schema.org/Movie")

>>> @ns_functions  # uses function name
... def add2(x):
...     return x + 2

>>> @ns_functions("add3")  # uses explicit name
... def add_three(x):
...     return x + 3

Parses an HTML document from a string constant. Returns the root node (or the result returned by a parser target). This function can be used to embed "HTML literals" in Python code.

To override the parser with a different HTMLParser you can pass it to the parser keyword argument.

The base_url keyword argument allows to set the original base URL of the document to support relative Paths when looking up external entities (DTD, XInclude, ...).

Parses an XML document or fragment from a string constant. Returns the root node (or the result returned by a parser target). This function can be used to embed "XML literals" in Python code, like in

>>> root = XML("<root><test/></root>")
>>> print(root.tag)
root

To override the parser with a different XMLParser you can pass it to the parser keyword argument.

The base_url keyword argument allows to set the original base URL of the document to support relative Paths when looking up external entities (DTD, XInclude, ...).

Parse the text and return a tuple (root node, ID dictionary). The root node is the same as returned by the XML() function. The dictionary contains string-element pairs. The dictionary keys are the values of ID attributes as defined by the DTD. The elements referenced by the ID are stored as dictionary values.

Note that you must not modify the XML tree if you use the ID dictionary. The results are undefined.

Creates an XPath evaluator for an ElementTree or an Element.

The resulting object can be called with an XPath expression as argument and XPath variables provided as keyword arguments.

Additional namespace declarations can be passed with the 'namespace' keyword argument. EXSLT regular expression support can be disabled with the 'regexp' boolean keyword (defaults to True). Smart strings will be returned for string results unless you pass smart_strings=False.

Convert XML to its C14N 2.0 serialised form.

If out is provided, it must be a file or file-like object that receives the serialised canonical XML output (text, not bytes) through its .write() method. To write to a file, open it in text mode with encoding "utf-8". If out is not provided, this function returns the output as text string.

Either xml_data (an XML string, tree or Element) or file (a file path or file-like object) must be provided as input.

The configuration options are the same as for the C14NWriterTarget.

Remove all namespace declarations from a subtree that are not used by any of the elements or attributes in that tree.

If a 'top_nsmap' is provided, it must be a mapping from prefixes to namespace URIs. These namespaces will be declared on the top element of the subtree before running the cleanup, which allows moving namespace declarations to the top of the tree.

If a 'keep_ns_prefixes' is provided, it must be a list of prefixes. These prefixes will not be removed as part of the cleanup.

Clear the global error log. Note that this log is already bound to a fixed size.

Note: since lxml 2.2, the global error log is local to a thread and this function will only clear the global error log of the current thread.

Parses an XML document or fragment from a string. Returns the root node (or the result returned by a parser target).

To override the default parser with a different parser you can pass it to the parser keyword argument.

The base_url keyword argument allows to set the original base URL of the document to support relative Paths when looking up external entities (DTD, XInclude, ...).

Parses an XML document from a sequence of strings. Returns the root node (or the result returned by a parser target).

To override the default parser with a different parser you can pass it to the parser keyword argument.

Return an ElementTree object loaded with source elements. If no parser is provided as second argument, the default parser is used.

The source can be any of the following:

• a file name/path
• a file object
• a file-like object
• a URL using the HTTP or FTP protocol

To parse from a string, use the fromstring() function instead.

Note that it is generally faster to parse from a file path or URL than from an open file object or file-like object. Transparent decompression from gzip compressed sources is supported (unless explicitly disabled in libxml2).

The base_url keyword allows setting a URL for the document when parsing from a file-like object. This is needed when looking up external entities (DTD, XInclude, ...) with relative paths.

Parses the source into a tuple containing an ElementTree object and an ID dictionary. If no parser is provided as second argument, the default parser is used.

Note that you must not modify the XML tree if you use the ID dictionary. The results are undefined.

Set a default parser for the current thread. This parser is used globally whenever no parser is supplied to the various parse functions of the lxml API. If this function is called without a parser (or if it is None), the default parser is reset to the original configuration.

Note that the pre-installed default parser is not thread-safe. Avoid the default parser in multi-threaded environments. You can create a separate parser for each thread explicitly or use a parser pool.

Delete all attributes with the provided attribute names from an Element (or ElementTree) and its descendants.

Attribute names can contain wildcards as in _Element.iter.

Example usage:

strip_attributes(root_element,
                 'simpleattr',
                 '{http://some/ns}attrname',
                 '{http://other/ns}*')

Delete all elements with the provided tag names from a tree or subtree. This will remove the elements and their entire subtree, including all their attributes, text content and descendants. It will also remove the tail text of the element unless you explicitly set the with_tail keyword argument option to False.

Tag names can contain wildcards as in _Element.iter.

Note that this will not delete the element (or ElementTree root element) that you passed even if it matches. It will only treat its descendants. If you want to include the root element, check its tag name directly before even calling this function.

Example usage:

strip_elements(some_element,
    'simpletagname',             # non-namespaced tag
    '{http://some/ns}tagname',   # namespaced tag
    '{http://some/other/ns}*'    # any tag from a namespace
    lxml.etree.Comment           # comments
    )

Delete all elements with the provided tag names from a tree or subtree. This will remove the elements and their attributes, but not their text/tail content or descendants. Instead, it will merge the text content and children of the element into its parent.

Tag names can contain wildcards as in _Element.iter.

Note that this will not delete the element (or ElementTree root element) that you passed even if it matches. It will only treat its descendants.

Example usage:

strip_tags(some_element,
    'simpletagname',             # non-namespaced tag
    '{http://some/ns}tagname',   # namespaced tag
    '{http://some/other/ns}*'    # any tag from a namespace
    Comment                      # comments (including their text!)
    )

Serialize an element to an encoded string representation of its XML tree.

Defaults to ASCII encoding without XML declaration. This behaviour can be configured with the keyword arguments 'encoding' (string) and 'xml_declaration' (bool). Note that changing the encoding to a non UTF-8 compatible encoding will enable a declaration by default.

You can also serialise to a Unicode string without declaration by passing the name 'unicode' as encoding (or the str function in Py3 or unicode in Py2). This changes the return value from a byte string to an unencoded unicode string.

The keyword argument 'pretty_print' (bool) enables formatted XML.

The keyword argument 'method' selects the output method: 'xml', 'html', plain 'text' (text content without tags), 'c14n' or 'c14n2'. Default is 'xml'.

With method="c14n" (C14N version 1), the options exclusive, with_comments and inclusive_ns_prefixes request exclusive C14N, include comments, and list the inclusive prefixes respectively.

With method="c14n2" (C14N version 2), the with_comments and strip_text options control the output of comments and text space according to C14N 2.0.

Passing a boolean value to the standalone option will output an XML declaration with the corresponding standalone flag.

The doctype option allows passing in a plain string that will be serialised before the XML tree. Note that passing in non well-formed content here will make the XML output non well-formed. Also, an existing doctype in the document tree will not be removed when serialising an ElementTree instance.

You can prevent the tail text of the element from being serialised by passing the boolean with_tail option. This has no impact on the tail text of children, which will always be serialised.

Serialize an element to an encoded string representation of its XML tree, stored in a list of partial strings.

This is purely for ElementTree 1.3 compatibility. The result is a single string wrapped in a list.

Serialize an element to the Python unicode representation of its XML tree.

Note that the result does not carry an XML encoding declaration and is therefore not necessarily suited for serialization to byte streams without further treatment.

The boolean keyword argument 'pretty_print' enables formatted XML.

The keyword argument 'method' selects the output method: 'xml', 'html' or plain 'text'.

You can prevent the tail text of the element from being serialised by passing the boolean with_tail option. This has no impact on the tail text of children, which will always be serialised.

Replace the global error log by an etree.PyErrorLog that uses the standard Python logging package.

Note that this disables access to the global error log from exceptions. Parsers, XSLT etc. will continue to provide their normal local error log.

Note: prior to lxml 2.2, this changed the error log globally. Since lxml 2.2, the global error log is local to a thread and this function will only set the global error log of the current thread.