API

Module contents

class mappet.Mappet(xml)[source]

Bases: mappet.mappet.Node

A node that may have children.

assign_dict(element, tag_name, value)[source]
assign_literal(element, tag_name, value)[source]

Assigns a literal.

If a given node doesn’t exist, it will be created.

Parameters:
  • element (etree.Element) – element to which we assign.
  • tag_name (string) – element name, if it itself doesn’t exists.
  • value – the value to assign
assign_sequence_or_set(element, tag_name, value)[source]
children(key=None, exact=False)[source]

Returns node’s children.

Parameters:
  • key – A key for filtering children by tagname.
  • exact – A flag to disable searching among aliases.
create(tag, value)[source]

Creates a node, if it doesn’t exist yet.

Unlike attribute access, this allows to pass a node’s name with hyphens. Those hyphens will be normalized automatically.

In case the required element already exists, raises an exception. Updating/overwriting should be done using update`.

has_children()[source]

Returns true if a node has children.

iter_children(key=None, exact=False)[source]

Iterates over children.

Parameters:
  • key – A key for filtering children by tagname.
  • exact – A flag to disable searching among aliases.
set(name, value)[source]

Assigns a new XML structure to the node.

A literal value, dict or list can be passed in. Works for all nested levels.

Dictionary: >>> m = Mappet(‘<root/>’) >>> m.head = {‘a’: ‘A’, ‘b’: {‘#text’: ‘B’, '@attr‘: ‘val’}} >>> m.head.to_str() ‘<head><a>A</a><b attr=”val”>B</b></head>’

List: >>> m.head = [{‘a’: i} for i in ‘ABC’] >>> m.head.to_str() ‘<head><a>A</a><a>B</a><a>C</a></head>’

Literals: >>> m.head.leaf = ‘A’ >>> m.head.leaf.get() ‘A’

sget(path, default=NoneNode)[source]

Enables access to nodes if one or more of them don’t exist.

Example: >>> m = Mappet(‘<root><tag attr1=”attr text”>text value</tag></root>’) >>> m.sget(‘tag’) text value >>> m.sget(‘tag.@attr1’) ‘attr text’ >>> m.sget(‘tag.#text’) ‘text value’ >>> m.sget(‘reply.vms_model_cars.car.0.params.doors’) NoneNode

Accessing nonexistent path returns None-like object with mocked converting functions which returns None: >>> m.sget(‘reply.fake_node’).to_dict() is None True

to_dict()[source]

Converts the lxml object to a dict.

to_str(pretty_print=False, encoding=None, **kw)[source]

Converts a node with all of it’s children to a string.

Remaining arguments are passed to etree.tostring as is.

Parameters:
  • pretty_print (bool) – whether to format the output
  • encoding (str) – which encoding to use (ASCII by default)
Return type:

str
Returns:

node’s representation as a string
update(**kwargs)[source]

Updating or creation of new simple nodes.

Each dict key is used as a tagname and value as text.

mappet.mappet module

Module for dynamic mapping of XML trees to Python objects.

class mappet.mappet.Literal(xml)[source]

Bases: mappet.mappet.Node

Represents a leaf in an XML tree.

get(default=None, callback=None)[source]

Returns leaf’s value.

class mappet.mappet.Mappet(xml)[source]

Bases: mappet.mappet.Node

A node that may have children.

assign_dict(element, tag_name, value)[source]
assign_literal(element, tag_name, value)[source]

Assigns a literal.

If a given node doesn’t exist, it will be created.

Parameters:
  • element (etree.Element) – element to which we assign.
  • tag_name (string) – element name, if it itself doesn’t exists.
  • value – the value to assign
assign_sequence_or_set(element, tag_name, value)[source]
children(key=None, exact=False)[source]

Returns node’s children.

Parameters:
  • key – A key for filtering children by tagname.
  • exact – A flag to disable searching among aliases.
create(tag, value)[source]

Creates a node, if it doesn’t exist yet.

Unlike attribute access, this allows to pass a node’s name with hyphens. Those hyphens will be normalized automatically.

In case the required element already exists, raises an exception. Updating/overwriting should be done using update`.

has_children()[source]

Returns true if a node has children.

iter_children(key=None, exact=False)[source]

Iterates over children.

Parameters:
  • key – A key for filtering children by tagname.
  • exact – A flag to disable searching among aliases.
set(name, value)[source]

Assigns a new XML structure to the node.

A literal value, dict or list can be passed in. Works for all nested levels.

Dictionary: >>> m = Mappet(‘<root/>’) >>> m.head = {‘a’: ‘A’, ‘b’: {‘#text’: ‘B’, '@attr‘: ‘val’}} >>> m.head.to_str() ‘<head><a>A</a><b attr=”val”>B</b></head>’

List: >>> m.head = [{‘a’: i} for i in ‘ABC’] >>> m.head.to_str() ‘<head><a>A</a><a>B</a><a>C</a></head>’

Literals: >>> m.head.leaf = ‘A’ >>> m.head.leaf.get() ‘A’

sget(path, default=NoneNode)[source]

Enables access to nodes if one or more of them don’t exist.

Example: >>> m = Mappet(‘<root><tag attr1=”attr text”>text value</tag></root>’) >>> m.sget(‘tag’) text value >>> m.sget(‘tag.@attr1’) ‘attr text’ >>> m.sget(‘tag.#text’) ‘text value’ >>> m.sget(‘reply.vms_model_cars.car.0.params.doors’) NoneNode

Accessing nonexistent path returns None-like object with mocked converting functions which returns None: >>> m.sget(‘reply.fake_node’).to_dict() is None True

to_dict()[source]

Converts the lxml object to a dict.

to_str(pretty_print=False, encoding=None, **kw)[source]

Converts a node with all of it’s children to a string.

Remaining arguments are passed to etree.tostring as is.

Parameters:
  • pretty_print (bool) – whether to format the output
  • encoding (str) – which encoding to use (ASCII by default)
Return type:

str
Returns:

node’s representation as a string
update(**kwargs)[source]

Updating or creation of new simple nodes.

Each dict key is used as a tagname and value as text.

class mappet.mappet.Node(xml)[source]

Bases: object

Base class representing an XML node.

getattr(key, default=None, callback=None)[source]

Getting the attribute of an element.

>>> xml = etree.Element('root')
>>> xml.text = 'text'
>>> Node(xml).getattr('text')
'text'
>>> Node(xml).getattr('text', callback=str.upper)
'TEXT'
>>> Node(xml).getattr('wrong_attr', default='default')
'default'
setattr(key, value)[source]

Sets an attribute on a node.

>>> xml = etree.Element('root')
>>> Node(xml).setattr('text', 'text2')
>>> Node(xml).getattr('text')
'text2'
>>> Node(xml).setattr('attr', 'val')
>>> Node(xml).getattr('attr')
'val'

mappet.helpers module

Helper functions.

mappet.helpers.to_bool(value)[source]
mappet.helpers.to_date(value)[source]
mappet.helpers.to_datetime(value)[source]
mappet.helpers.to_float(value)[source]
mappet.helpers.to_int(value)[source]
mappet.helpers.to_str(value)[source]

Represents values as unicode strings to support diacritics.

mappet.helpers.to_time(value)[source]
mappet.helpers.from_bool(value)[source]
mappet.helpers.from_date(value)[source]
mappet.helpers.from_datetime(value)[source]
mappet.helpers.from_float(value)[source]
mappet.helpers.from_int(value)[source]
mappet.helpers.from_str(value)[source]
mappet.helpers.from_time(value)[source]
mappet.helpers.normalize_tag(tag)[source]

Normalizes tag name.

>>> normalize_tag('tag-NaMe')
'tag_name'
mappet.helpers.etree_to_dict(t)[source]

Converts an lxml.etree object to Python dict.

>>> etree_to_dict(etree.Element('root'))
{'root': None}
Parameters:t (etree.Element) – lxml tree to convert
Returns d:a dict representing the lxml tree t
Return type:dict
mappet.helpers.dict_to_etree(d, root)[source]

Converts a dict to lxml.etree object.

>>> dict_to_etree({'root': {'#text': 'node_text', '@attr': 'val'}}, etree.Element('root'))
'<root><root attr="val">node_text</root></root>'
Parameters:
  • d (dict) – dict representing the XML tree
  • root (etree.Element) – XML node which will be assigned the resulting tree
Returns:

Textual representation of the XML tree
Return type:

str