def clean_indentation(element, level=0, spaces_per_level=2, trailing_indent=True):

"""Set indentation of XML element and its sub-elements.

Copied and pasted from https://effbot.org/zone/element-lib.htm#prettyprint.

It walks your tree and adds spaces and newlines so the tree is

printed in a nice way.

Parameters

----------

level : int

Indentation level for the element passed in (default 0)

spaces_per_level : int

Number of spaces per indentation level (default 2)

trailing_indent : bool

Whether or not to add indentation after closing the element

"""

i = "\n" + level*spaces_per_level*" "

# ensure there's always some tail for the element passed in

if not element.tail:

element.tail = ""

if len(element):

if not element.text or not element.text.strip():

element.text = i + spaces_per_level*" "

if trailing_indent and (not element.tail or not element.tail.strip()):

element.tail = i

for sub_element in element:

# `trailing_indent` is intentionally not forwarded to the recursive

# call. Any child element of the topmost element should add

# indentation at the end to ensure its parent's indentation is

# correct.

clean_indentation(sub_element, level+1, spaces_per_level)

if not sub_element.tail or not sub_element.tail.strip():

sub_element.tail = i

else:

if trailing_indent and level and (not element.tail or not element.tail.strip()):

element.tail = i

def get_text(elem, name, default=None):

"""Retrieve text of an attribute or subelement.

Parameters

----------

elem : lxml.etree._Element

Element from which to search

name : str

Name of attribute/subelement

default : object

A defult value to return if matching attribute/subelement exists

Returns

-------

str

Text of attribute or subelement

"""

if name in elem.attrib:

return elem.get(name, default)

else:

child = elem.find(name)

return child.text if child is not None else default

def get_elem_list(elem, name, dtype=int):

"""Helper function to get a list of values from an elem

Parameters

----------

elem : lxml.etree._Element

XML element that should contain a tuple

name : str

Name of the subelement to obtain tuple from

dtype : data-type

The type of each element in the tuple

Returns

-------

list of dtype

Data read from the list

"""

text = get_text(elem, name)

if text is not None:

return [dtype(x) for x in text.split()]