COT.xml_file module

Reading, editing, and writing XML files.

class XML[source]

Bases: object

Class capable of reading, editing, and writing XML files.

classmethod add_child(parent, new_child, ordering=None, known_namespaces=None)[source]

Add the given child element under the given parent element.

Parameters:
  • parent (xml.etree.ElementTree.Element) – Parent element
  • new_child (xml.etree.ElementTree.Element) – Child element to attach
  • ordering (list) – (Optional) List describing the expected ordering of child tags under the parent; if a new child element is created, its placement under the parent will respect this sequence.
  • known_namespaces (list) – (Optional) List of well-understood XML namespaces. If a new child is created, and ordering is given, any tag (new or existing) that is encountered but not accounted for in ordering will result in COT logging a warning iff the unaccounted-for tag is in a known namespace.
classmethod find_all_children(parent, tag, attrib={})[source]

Find all matching child elements under the specified parent element.

Parameters:
  • parent (xml.etree.ElementTree.Element) – Parent element
  • tag (str) – Child tag to match on
  • attrib (dict) – Child attributes to match on
Return type:

list of xml.etree.ElementTree.Element instances

classmethod find_child(parent, tag, attrib={}, required=False)[source]

Find the unique child element under the specified parent element.

Raises:
  • LookupError – if more than one matching child is found
  • KeyError – if no matching child is found and required is True
Parameters:
  • parent (xml.etree.ElementTree.Element) – Parent element
  • tag (str) – Child tag to match on
  • attrib (dict) – Child attributes to match on
  • required (boolean) – Whether to raise an error if no child exists
Return type:

xml.etree.ElementTree.Element

classmethod get_ns(text)[source]

Get the namespace prefix from an XML element or attribute name.

read_xml(xml_file)[source]

Read the given XML file and store it in memory.

The memory representation is available as self.tree and self.root.

Raises:
  • xml.etree.ElementTree.ParseError – if parsing fails under Python 2.7 or later
  • xml.parsers.expat.ExpatError – if parsing fails under Python 2.6
Parameters:

xml_file (str) – File path to read.

register_namespace(prefix, URI)[source]

Record a particular mapping between a namespace prefix and URI.

Parameters:
classmethod set_or_make_child(parent, tag, text=None, attrib=None, ordering=None, known_namespaces=None)[source]

Update or create a child element under the specified parent element.

Parameters:
  • parent (xml.etree.ElementTree.Element) – Parent element
  • tag (str) – Child element text tag to find or create
  • text (str) – Value to set the child’s text attribute to
  • attrib (dict) – Dict of child attributes to match on while searching and set in the final child element
  • ordering (list) – See add_child()
  • known_namespaces (list) – See add_child()
Returns:

New or updated child Element.

Return type:

xml.etree.ElementTree.Element

classmethod strip_ns(text)[source]

Remove a namespace prefix from an XML element or attribute name.

write_xml(file)[source]

Write pretty XML out to the given file.

Parameters:file (str) – Filename to write to
xml_reindent(parent, depth)[source]

Recursively add indentation to XML to make it look nice.

Parameters:
  • parent (xml.etree.ElementTree.Element) – Current parent element
  • depth (int) – How far down the rabbit hole we have recursed. Increments by 2 for each successive level of nesting.