XMLWriter¶

class astropy.utils.xml.writer.XMLWriter(file)[source]¶

Bases: object

A class to write well-formed and nicely indented XML.

Use like this:

w = XMLWriter(fh)
with w.tag('html'):
    with w.tag('body'):
        w.data('This is the content')

Which produces:

<html>
 <body>
  This is the content
 </body>
</html>

Parameters

filewritable file-like object.

Methods Summary

`close`(self, id)	Closes open elements, up to (and including) the element identified by the given identifier.
`comment`(self, comment)	Adds a comment to the output stream.
`data`(self, text)	Adds character data to the output stream.
`element`(self, tag[, text, wrap, attrib])	Adds an entire element.
`end`(self[, tag, indent, wrap])	Closes the current element (opened by the most recent call to `start`).
`flush`(self)
`get_indentation`(self)	Returns the number of indentation levels the file is currently in.
`get_indentation_spaces`(self[, offset])	Returns a string of spaces that matches the current indentation level.
`object_attrs`(obj, attrs)	Converts an object with a bunch of attributes on an object into a dictionary for use by the `XMLWriter`.
`start`(self, tag[, attrib])	Opens a new element.
`tag`(self, tag[, attrib])	A convenience method for creating wrapper elements using the `with` statement.
`xml_cleaning_method`(self[, method])	Context manager to control how XML data tags are cleaned (escaped) to remove potentially unsafe characters or constructs.

Methods Documentation

close(self, id)[source]¶

Closes open elements, up to (and including) the element identified by the given identifier.

Parameters

idint: Element identifier, as returned by the start method.

comment(self, comment)[source]¶

Adds a comment to the output stream.

Parameters

commentstr: Comment text, as a Unicode string.

data(self, text)[source]¶

Adds character data to the output stream.

Parameters

textstr: Character data, as a Unicode string.

element(self, tag, text=None, wrap=False, attrib={}, **extra)[source]¶: Adds an entire element. This is the same as calling start, data, and end in sequence. The text argument can be omitted.

end(self, tag=None, indent=True, wrap=False)[source]¶

Closes the current element (opened by the most recent call to start).

Parameters

tagstr: Element name. If given, the tag must match the start tag. If omitted, the current element is closed.

flush(self)[source]¶

get_indentation(self)[source]¶: Returns the number of indentation levels the file is currently in.

get_indentation_spaces(self, offset=0)[source]¶: Returns a string of spaces that matches the current indentation level.

static object_attrs(obj, attrs)[source]¶

Converts an object with a bunch of attributes on an object into a dictionary for use by the XMLWriter.

Parameters

objobject: Any Python object
attrssequence of str: Attribute names to pull from the object

Returns

attrsdict: Maps attribute names to the values retrieved from obj.attr. If any of the attributes is None, it will not appear in the output dictionary.

start(self, tag, attrib={}, **extra)[source]¶

Opens a new element. Attributes can be given as keyword arguments, or as a string/string dictionary. The method returns an opaque identifier that can be passed to the close() method, to close all open elements up to and including this one.

Parameters

tagstr: The element name
attribdict of str -> str: Attribute dictionary. Alternatively, attributes can be given as keyword arguments.

Returns

idint: Returns an element identifier.

tag(self, tag, attrib={}, **extra)[source]¶

A convenience method for creating wrapper elements using the with statement.

Examples

>>> with writer.tag('foo'):  
...     writer.element('bar')
... # </foo> is implicitly closed here
...

Parameters are the same as to start.

xml_cleaning_method(self, method='escape_xml', **clean_kwargs)[source]¶

Context manager to control how XML data tags are cleaned (escaped) to remove potentially unsafe characters or constructs.

The default (method='escape_xml') applies brute-force escaping of certain key XML characters like <, >, and & to ensure that the output is not valid XML.

In order to explicitly allow certain XML tags (e.g. link reference or emphasis tags), use method='bleach_clean'. This sanitizes the data string using the clean function of the https://bleach.readthedocs.io/en/latest/clean.html package. Any additional keyword arguments will be passed directly to the clean function.

Finally, use method='none' to disable any sanitization. This should be used sparingly.

Example:

w = writer.XMLWriter(ListWriter(lines))
with w.xml_cleaning_method('bleach_clean'):
    w.start('td')
    w.data('<a href="https://google.com">google.com</a>')
    w.end()

Parameters

methodstr: Cleaning method. Allowed values are “escape_xml”, “bleach_clean”, and “none”.
**clean_kwargskeyword args: Additional keyword args that are passed to the bleach.clean() function.

Navigation

XMLWriter¶