6.3. The ElementTree() constructor

6.3. The `ElementTree()` constructor

To create a new, empty document, use this constructor. It returns a new ElementTree instance.

etree.ElementTree ( element=None, file=None )

element

An Element instance to be used as the root element.

file

To construct an ElementTree that represents an existing file, pass either a writeable file object, or a string containing the name of the file. Do not use the element argument; if you do, the file argument will be ignored.

For example, to transform a file named balrog.xml into an ElementTree, use this statement:

balrogTree = etree.ElementTree ( file='balrog.xml' )

Exceptions that can be raised by this constructor include:

IOError

If the file is nonexistent or unreadable.

etree.XMLSyntaxError

If the file is readable, but its contents are not well-formed XML.

The returned exception value has an .error_log attribute that you can display to find out where in the file errors occurred. Here is an example:

>>> try:
...   bad = etree.fromstring ( "<a>\n<<oops>\n</a>" )
... except etree.XMLSyntaxError as detail:
...   pass
... 
>>> detail
<etree.XMLSyntaxError instance at 0xb7eba10c>
>>> detail.error_log
<string>:2:FATAL:PARSER:ERR_NAME_REQUIRED: StartTag: invalid element name
<string>:3:FATAL:PARSER:ERR_TAG_NAME_MISMATCH: Opening and ending tag mismatch: oops line 2 and a
<string>:3:FATAL:PARSER:ERR_TAG_NOT_FINISHED: Premature end of data in tag a line 1
>>>

Python XML processing with lxml

6.3. The ElementTree() constructor

Python XML processing with `lxml`

6.3. The `ElementTree()` constructor