quandyfactory / dicttoxml

Simple library to convert a Python dictionary or other native data type into a valid XML string.
GNU General Public License v2.0
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Summary

Converts a Python dictionary or other native data type into a valid XML string.

Details

Supports item (int, float, long, decimal.Decimal, bool, str, unicode, datetime, none and other number-like objects) and collection (list, set, tuple and dict, as well as iterable and dict-like objects) data types, with arbitrary nesting for the collections. Items with a datetime type are converted to ISO format strings. Items with a None type become empty XML elements.

The root object passed into the dicttoxml method can be any of the supported data types.

To satisfy XML syntax, the method prepends an <?xml version="1.0" encoding="UTF-8" ?> element and wraps the output in a <root> ... </root> element. However, this can be disabled to create XML snippets. Alternately, a custom root element can be specified by passing in the optional custom_root=foobar argument.

For lists of items, if each item is also a collection data type (lists, dict), the elements of that item are wrapped in a generic <item> ... </item> element.

Each element includes an optional type attribute with the data type. By default, the type attribute it included but it can be excluded by passing an optional attr_type=False argument when calling the dicttoxml method.

Note: datetime data types are converted into ISO format strings, and unicode and datetime data types get a str attribute.

Python -> XML
integer   int
long      long
float     float
Decimal   number
string    str
unicode   str
datetime  str
None      null
boolean   bool
list      list
set       list
tuple     list
dict      dict

Elements with an unsupported data type raise a TypeError exception.

If an element name is invalid XML, it is rendered with the name "key" and the invalid name is included as a name attribute. E.g. { "^.{0,256}$": "foo" } would be rendered <key name="^.{0,256}$">foo</key>. An exception is element names with spaces, which are converted to underscores.

This module should work in Python 3.6+. You might be able to get it to work in Python 2.x but that is no longer supported.

Installation

The dicttoxml module is published on the Python Package Index, so you can install it using pip.

pip install dicttoxml

Alternately, you can download the tarballed installer - dicttoxml-[VERSION].tar.gz - for this package from the dist directory on github and uncompress it. Then, from a terminal or command window, navigate into the unzipped folder and type the command:

python setup.py install

That should be all you need to do.

Basic Usage

Once installed, import the library into your script and convert a dict into xml by running the dicttoxml function:

>>> import dicttoxml
>>> xml = dicttoxml.dicttoxml(some_dict)

Alternately, you can import the dicttoxml() function from the library.

>>> from dicttoxml import dicttoxml
>>> xml = dicttoxml(some_dict)

That's it!

JSON to XML

Let's say you want to fetch a JSON object from a URL and convert it into XML. Here's how you can do that:

>>> import json
>>> import urllib
>>> import dicttoxml
>>> page = urllib.urlopen('http://quandyfactory.com/api/example')
>>> content = page.read()
>>> obj = json.loads(content)
>>> print(obj)
{u'mylist': [u'foo', u'bar', u'baz'], u'mydict': {u'foo': u'bar', u'baz': 1}, u'ok': True}
>>> xml = dicttoxml.dicttoxml(obj)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><mylist><item type="str">foo</item><item type="str">bar</item><item type="str">baz</item></mylist><mydict><foo type="str">bar</foo><baz type="int">1</baz></mydict><ok type="bool">true</ok></root>

It's that simple.

XML Snippet

Instead of creating a full XML document, you can create an XML snippet for inclusion into another XML document.

Continuing with the example from above:

>>> xml_snippet = dicttoxml.dicttoxml(obj, root=False)
>>> print(xml_snippet)
<mylist><item type="str">foo</item><item type="str">bar</item><item type="str">baz</item></mylist><mydict><foo type="str">bar</foo><baz type="int">1</baz></mydict><ok type="bool">true</ok>

With the optional root argument set to False, the method converts the dict into XML without including an <?xml> prolog or a <root> element to enclose all the other elements.

Custom Root

By default, dicttoxml wraps all the elements in a <root> ... </root> element. Starting in version 1.5, you can change the name of the root element to something else by passing an optional custom_root=some_custom_root argument to the dicttoxml method.

Using our example:

>>> xml = dicttoxml.dicttoxml(obj, custom_root='some_custom_root')
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><some_custom_root><mydict><foo>bar</foo><baz>1</baz></mydict><mylist><item>foo</item><item>bar</item><item>baz</item></mylist><ok>true</ok></some_custom_root>

As you can see, the name of the root element has changed to some_custom_root.

Omit XML Declaration

Perhaps you want your outputted XML to have a root but no XML declaration. Starting with version 1.7.15, can call dicttoxml with the optional xml_declaration argument set to False:

>>> xml = dicttoxml.dicttoxml(xml_declaration=False)
>>> print(xml)
<root><ok type="bool">true</ok><mylist type="list"><item type="str">foo</item><item type="str">bar</item><item type="str">baz</item></mylist><mydict type="dict"><foo type="str">bar</foo><baz type="int">1</baz></mydict></root>

As you can see, the XML declaration has been omitted.

Disable Type Attributes

By default, dicttoxml includes a type attribute for each element. Starting in version 1.4, you can turn this off by passing an optional attr_type=False argument to the dicttoxml method.

Using our example:

>>> xml = dicttoxml.dicttoxml(obj, attr_type=False)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><mydict><foo>bar</foo><baz>1</baz></mydict><mylist><item>foo</item><item>bar</item><item>baz</item></mylist><ok>true</ok></root>

As you can see, the only difference is that the type attributes are now absent.

Change or Suppress XML Encoding Attribute

By default, dicttoxml renders the XML element with an encoding="UTF-8" attribute. Starting in version 1.7.6, you can change the encoding by using the optional encoding argument to the dicttoxml method. For example, to render an XML file with encoding "ISO-8859-1", you would call:

>>> xml = dicttoxml.dicttoxml(obj, encoding="ISO-8859-1")

Or if you prefer, you can suppress the encoding attribute altogether by setting the optional include_encoding argument to False:

>>> xml = dicttoxml.dicttoxml(obj, include_encoding=False)

Again, by default, the include_encoding argument is set to True and the encoding argument is set to UTF-8.

Unique ID Attributes

Starting in version 1.1, you can set an optional ids parameter so that dicttoxml gives each element a unique id attribute.

With the ids flag on, the function generates a unique randomly-generated ID for each element based on the parent element in the form parent_unique. For list items, the id is in the form parent_unique_index.

Continuing with our example:

>>> xml_with_ids = dicttoxml.dicttoxml(obj, ids=True)
>>> print(parseString(xml_with_ids).toprettyxml())
<?xml version="1.0" ?>
<root>
        <mylist id="root_160980" type="list">
                <item id="mylist_609405_1" type="str">foo</item>
                <item id="mylist_609405_2" type="str">bar</item>
                <item id="mylist_609405_3" type="str">baz</item>
        </mylist>
        <mydict id="root_140407" type="dict">
                <foo id="mydict_260437" type="str">bar</foo>
                <baz id="mydict_111194" type="int">1</baz>
        </mydict>
        <ok id="root_612831" type="bool">true</ok>
</root>

Note that the default XML output remains the same as previous, so as not to break compatibility for existing uses.

Dict-Like and Iterable Objects

Starting in version 1.3, dicttoxml accepts dict-like objects that are derived from the dict base class and treats them like dicts. For example:

>>> import collections
>>> dictlike = collections.OrderedDict({'foo': 1, 'bar': 2, 'baz': 3})
>>> xml = dicttoxml.dicttoxml(dictlike)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><baz type="int">3</baz><foo type="int">1</foo><bar type="int">2</bar></root>

Also starting in version 1.3, dicttoxml accepts iterable objects and treats them like lists. For example:

>>> myiter = range(1,11)
>>> xml = dicttoxml.dicttoxml(myiter)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><item type="int">1</item><item type="int">2</item><item type="int">3</item><item type="int">4</item><item type="int">5</item><item type="int">6</item><item type="int">7</item><item type="int">8</item><item type="int">9</item><item type="int">10</item></root>

As always, this remains compatible with arbitrary nesting of objects and types.

Define Custom Item Names

Starting in version 1.7, if you don't want item elements in a list to be called 'item', you can specify the element name using a function that takes the parent element name (i.e. the list name) as an argument.

>>> import dicttoxml
>>> obj = {u'mylist': [u'foo', u'bar', u'baz'], u'mydict': {u'foo': u'bar', u'baz': 1}, u'ok': True}
>>> my_item_func = lambda x: 'list_item'
>>> xml = dicttoxml.dicttoxml(obj, item_func=my_item_func)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><mydict type="dict"><foo type="str">bar</foo><baz type="int">1</baz></mydict><mylist type="list"><list_item type="str">foo</list_item><list_item type="str">bar</list_item><list_item type="str">baz</list_item></mylist><ok type="bool">True</ok></root>

The benefit of taking the parent element name as an argument is that you can write the function to do something with it. Let's say you have an object with some lists of specific items:

>>> obj = {'shrubs': ['abelia', 'aralia', 'aucuba', 'azalea', 'bamboo', 'barberry', 'bluebeard', 'boxwood', 'camellia', 'dogwood', 'elderberry', 'enkianthus', 'firethorn', 'fuchsia', 'hazel', 'heath', 'heather', 'holly', 'honeysuckle', 'hydrangea', 'laurel', 'lilac', 'mock orange', 'rhododendron', 'rose', 'rose of sharon', 'rosemary', 'smokebush', 'spirea', 'sweetbox', 'viburnum', 'weigela', 'yucca'], 'trees': ['ash', 'aspen', 'birch', 'butternut', 'cedar', 'cottonwood', 'elm', 'fir', 'hawthorn', 'larch', 'locust', 'maple', 'oak', 'pine', 'spruce', 'sycamore', 'willow']}

You can define each item name to be the singular of its parent name by returning all but the last character.

>>> my_item_func = lambda x: x[:-1]
>>> xml = dicttoxml.dicttoxml(obj, item_func=my_item_func)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><shrubs type="list"><shrub type="str">abelia</shrub><shrub type="str">aralia</shrub><shrub type="str">aucuba</shrub><shrub type="str">azalea</shrub><shrub type="str">bamboo</shrub><shrub type="str">barberry</shrub><shrub type="str">bluebeard</shrub><shrub type="str">boxwood</shrub><shrub type="str">camellia</shrub><shrub type="str">dogwood</shrub><shrub type="str">elderberry</shrub><shrub type="str">enkianthus</shrub><shrub type="str">firethorn</shrub><shrub type="str">fuchsia</shrub><shrub type="str">hazel</shrub><shrub type="str">heath</shrub><shrub type="str">heather</shrub><shrub type="str">holly</shrub><shrub type="str">honeysuckle</shrub><shrub type="str">hydrangea</shrub><shrub type="str">laurel</shrub><shrub type="str">lilac</shrub><shrub type="str">mock orange</shrub><shrub type="str">rhododendron</shrub><shrub type="str">rose</shrub><shrub type="str">rose of sharon</shrub><shrub type="str">rosemary</shrub><shrub type="str">smokebush</shrub><shrub type="str">spirea</shrub><shrub type="str">sweetbox</shrub><shrub type="str">viburnum</shrub><shrub type="str">weigela</shrub><shrub type="str">yucca</shrub></shrubs><trees type="list"><tree type="str">ash</tree><tree type="str">aspen</tree><tree type="str">birch</tree><tree type="str">butternut</tree><tree type="str">cedar</tree><tree type="str">cottonwood</tree><tree type="str">elm</tree><tree type="str">fir</tree><tree type="str">hawthorn</tree><tree type="str">larch</tree><tree type="str">locust</tree><tree type="str">maple</tree><tree type="str">oak</tree><tree type="str">pine</tree><tree type="str">spruce</tree><tree type="str">sycamore</tree><tree type="str">willow</tree></trees></root>

Of course, this can be combined with other optional arguments, like disabling type attributes or custom root element names.

CDATA

Starting in version 1.7.1, you can wrap values in CDATA by setting the optional cdata argument to True.

>>> import dicttoxml
>>> obj = {u'mylist': [u'foo', u'bar', u'baz'], u'mydict': {u'foo': u'bar', u'baz': 1}, u'ok': True}
>>> xml = dicttoxml.dicttoxml(obj, cdata=True)
>>> print(xml)
<?xml version="1.0" encoding="UTF-8" ?><root><mydict type="dict"><foo type="str"><![CDATA[bar]]></foo><baz type="int"><![CDATA[1]]></baz></mydict><mylist type="list"><item type="str"><![CDATA[foo]]></item><item type="str"><![CDATA[bar]]></item><item type="str"><![CDATA[baz]]></item></mylist><ok type="bool"><![CDATA[True]]></ok></root>

If you do not set cdata to True, the default value is False and values are not wrapped.

Return a String

By default, dicttoxml outputs the generated XML as a bytes object:

>>> xml = dicttoxml.dicttoxml(obj)
>>> type(xml).__name__
'bytes'

Starting in version 1.7.14, when you call the dicttoxml function, you can set an optional return_bytes argument to False to return a str object instead:

>>> xml = dicttoxml.dicttoxml(obj, return_bytes=False)
>>> type(xml).__name__
'str'

But by default, return_bytes is set to True.

Pretty-Printing

As they say, Python comes with batteries included. You can easily syntax-check and pretty-print your XML using Python's xml.dom.minidom module.

Again, continuing with our example:

>>> from xml.dom.minidom import parseString
>>> dom = parseString(xml)
>>> print(dom.toprettyxml())
<?xml version="1.0" ?>
<root>
    <mylist type="list">
        <item type="str">foo</item>
        <item type="str">bar</item>
        <item type="str">baz</item>
    </mylist>
    <mydict type="dict">
        <foo type="str">bar</foo>
        <baz type="int">1</baz>
    </mydict>
    <ok type="bool">true</ok>
</root>

This makes the XML easier to read. If it is not well-formed, the xml parser will raise an exception.

Debugging

You can enable debugging informationby calling the set_debug() method:

>>> import dicttoxml
>>> dicttoxml.set_debug(debug=True)
Debug mode is on. Events are logged at: dicttoxml.log
>>> xml = dicttoxml.dicttoxml(some_dict)

By default, debugging information is logged to dicttoxml.log, but you can change this:

>>> dicttoxml.set_debug(debug=True, filename='/path/to/some_other_filename.log')
Debug mode is on. Events are logged at: some_other_filename.log

To turn debug mode off, just call set_debug with an argument of False:

>>> dicttoxml.set_debug(debug=False)

If you encounter any errors in the code, please file an issue on github: https://github.com/quandyfactory/dicttoxml/issues.

Author

Version

Revision History

Version 1.7.16

Version 1.7.15

Version 1.7.14

Version 1.7.13

Version 1.7.12

Version 1.7.11

Version 1.7.9

Version 1.7.8

Version 1.7.7

Version 1.7.6

Version 1.7.5

Version 1.7.4

Version 1.7.3

Version 1.7.2

Version 1.7.1

Version 1.7

Version 1.6.6

Version 1.6.5

Version 1.6.4

Version 1.6.3

Version 1.6.2

Version 1.6.1

Version 1.6.0

Version 1.5.9

Version 1.5.8

Version 1.5.7

Version 1.5.6

Version 1.5.5

Version 1.5.4

Version 1.5.3

Version 1.5.2

Version 1.5.1

Version 1.5

Version 1.4

Version 1.3.7

Version 1.3.6

Version 1.3.5

Version 1.3.4

Version 1.3.3

Version 1.3.2

Version 1.3.1

Version 1.3

Version 1.2

Version 1.1.2

Version 1.1.1

Version 1.1

Verson 1.0

Version 0.9.1

Version 0.9

Version 0.8

Version 0.7

Version 0.6

Version 0.5

Version 0.4

Version 0.3

Version 0.2

Version 0.1

Copyright and Licence

Copyright 2012 by Ryan McGreal.

Released under the GNU General Public Licence, Version 2:
http://www.gnu.org/licenses/old-licenses/gpl-2.0.html