Xmljson Documentation Release 0.2.0
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xmljson Documentation Release 0.2.0 S Anand Nov 21, 2018 Contents 1 About 3 2 Convert data to XML 5 3 Convert XML to data 7 4 Conventions 9 5 Options 11 6 Installation 13 7 Simple CLI utility 15 8 Roadmap 17 9 More information 19 9.1 Contributing............................................... 19 9.2 Credits.................................................. 21 9.3 History.................................................. 22 9.4 Indices and tables............................................ 23 i ii xmljson Documentation, Release 0.2.0 xmljson converts XML into Python dictionary structures (trees, like in JSON) and vice-versa. Contents 1 xmljson Documentation, Release 0.2.0 2 Contents CHAPTER 1 About XML can be converted to a data structure (such as JSON) and back. For example: <employees> <person> <name value="Alice"/> </person> <person> <name value="Bob"/> </person> </employees> can be converted into this data structure (which also a valid JSON object): { "employees": [{ "person":{ "name":{ "@value":"Alice" } } }, { "person":{ "name":{ "@value":"Bob" } } }] } This uses the BadgerFish convention that prefixes attributes with @. The conventions supported by this library are: • Abdera: Use "attributes" for attributes, "children" for nodes • BadgerFish: Use "$" for text content, @ to prefix attributes 3 xmljson Documentation, Release 0.2.0 • Cobra: Use "attributes" for sorted attributes (even when empty), "children" for nodes, values are strings • GData: Use "$t" for text content, attributes added as-is • Parker: Use tail nodes for text content, ignore attributes • Yahoo Use "content" for text content, attributes added as-is 4 Chapter 1. About CHAPTER 2 Convert data to XML To convert from a data structure to XML using the BadgerFish convention: >>> from xmljson import badgerfish as bf >>> bf.etree({'p':{'@id':'main','$':'Hello','b':'bold'}}) This returns an array of etree.Element structures. In this case, the result is identical to: >>> from xml.etree.ElementTree import fromstring >>> [fromstring('<p id="main">Hello<b>bold</b></p>')] The result can be inserted into any existing root etree.Element: >>> from xml.etree.ElementTree import Element, tostring >>> result= bf.etree({'p':{'@id':'main'}}, root=Element('root')) >>> tostring(result) '<root><p id="main"/></root>' This includes lxml.html as well: >>> from lxml.html import Element, tostring >>> result= bf.etree({'p':{'@id':'main'}}, root=Element('html')) >>> tostring(result, doctype='<!DOCTYPE html>') '<!DOCTYPE html>\n<html><p id="main"></p></html>' For ease of use, strings are treated as node text. For example, both the following are the same: >>> bf.etree({'p':{'$':'paragraph text'}}) >>> bf.etree({'p':'paragraph text'}) By default, non-string values are converted to strings using Python’s str, except for booleans – which are converted into true and false (lower case). Override this behaviour using xml_fromstring: >>> tostring(bf.etree({'x': 1.23,'y': True}, root=Element('root'))) '<root><y>true</y><x>1.23</x></root>' (continues on next page) 5 xmljson Documentation, Release 0.2.0 (continued from previous page) >>> from xmljson import BadgerFish # import the class >>> bf_str= BadgerFish(xml_tostring=str) # convert using str() >>> tostring(bf_str.etree({'x': 1.23,'y': True}, root=Element('root'))) '<root><y>True</y><x>1.23</x></root>' If the data contains invalid XML keys, these can be dropped via invalid_tags='drop' in the constructor: >>> bf_drop= BadgerFish(invalid_tags='drop') >>> data= bf_drop.etree({'$':'1','x':'1'}, root=Element('root')) # Drops ,!invalid <$> tag >>> tostring(data) '<root>1<x>1</x></root>' 6 Chapter 2. Convert data to XML CHAPTER 3 Convert XML to data To convert from XML to a data structure using the BadgerFish convention: >>> bf.data(fromstring('<p id="main">Hello<b>bold</b></p>')) {"p": {"$": "Hello", "@id": "main", "b": {"$": "bold"}}} To convert this to JSON, use: >>> from json import dumps >>> dumps(bf.data(fromstring('<p id="main">Hello<b>bold</b></p>'))) '{"p": {"b": {"$": "bold"}, "@id": "main", "$": "Hello"}}' To preserve the order of attributes and children, specify the dict_type as OrderedDict (or any other dictionary- like type) in the constructor: >>> from collections import OrderedDict >>> from xmljson import BadgerFish # import the class >>> bf= BadgerFish(dict_type=OrderedDict) # pick dict class By default, values are parsed into boolean, int or float where possible (except in the Yahoo method). Override this behaviour using xml_fromstring: >>> dumps(bf.data(fromstring('<x>1</x>'))) '{"x": {"$": 1}}' >>> bf_str= BadgerFish(xml_fromstring= False) # Keep XML values as strings >>> dumps(bf_str.data(fromstring('<x>1</x>'))) '{"x": {"$": "1"}}' >>> bf_str= BadgerFish(xml_fromstring=repr) # Custom string parser '{"x": {"$": "\'1\'"}}' xml_fromstring can be any custom function that takes a string and returns a value. In the example below, only the integer 1 is converted to an integer. Everything else is retained as a float: >>> def convert_only_int(val): ... return int(val) if val.isdigit() else val (continues on next page) 7 xmljson Documentation, Release 0.2.0 (continued from previous page) >>> bf_int= BadgerFish(xml_fromstring=convert_only_int) >>> dumps(bf_int.data(fromstring('<p><x>1</x><y>2.5</y><z>NaN</z></p>'))) '{"p": {"x": {"$": 1}, "y": {"$": "2.5"}, "z": {"$": "NaN"}}}' 8 Chapter 3. Convert XML to data CHAPTER 4 Conventions To use a different conversion method, replace BadgerFish with one of the other classes. Currently, these are supported: >>> from xmljson import abdera # == xmljson.Abdera() >>> from xmljson import badgerfish # == xmljson.BadgerFish() >>> from xmljson import cobra # == xmljson.Cobra() >>> from xmljson import gdata # == xmljson.GData() >>> from xmljson import parker # == xmljson.Parker() >>> from xmljson import yahoo # == xmljson.Yahoo() 9 xmljson Documentation, Release 0.2.0 10 Chapter 4. Conventions CHAPTER 5 Options Conventions may support additional options. The Parker convention absorbs the root element by default. parker.data(preserve_root=True) preserves the root instance: >>> from xmljson import parker, Parker >>> from xml.etree.ElementTree import fromstring >>> from json import dumps >>> dumps(parker.data(fromstring('<x><a>1</a><b>2</b></x>'))) '{"a": 1, "b": 2}' >>> dumps(parker.data(fromstring('<x><a>1</a><b>2</b></x>'), preserve_root=True)) '{"x": {"a": 1, "b": 2}}' 11 xmljson Documentation, Release 0.2.0 12 Chapter 5. Options CHAPTER 6 Installation This is a pure-Python package built for Python 2.7+ and Python 3.0+. To set up: pip install xmljson 13 xmljson Documentation, Release 0.2.0 14 Chapter 6. Installation CHAPTER 7 Simple CLI utility After installation, you can benefit from using this package as simple CLI utility. By now only XML to JSON conver- sion supported. Example: $ python -m xmljson -h usage: xmljson [-h] [-o OUT_FILE] [-d {abdera,badgerfish,cobra,gdata,parker,xmldata,yahoo}] [in_file] positional arguments: in_file defaults to stdin optional arguments: -h, --help show this help message and exit -o OUT_FILE, --out_file OUT_FILE defaults to stdout -d {abdera,badgerfish,...}, --dialect {...} defaults to parker $ python -m xmljson -d parker tests/mydata.xml { "foo": "spam", "bar": 42 } This is a typical UNIX filter program: it reads file (or stdin), processes it in some way (convert XML to JSON in this case), then prints it to stdout (or file). Example with pipe: $ some-xml-producer | python -m xmljson | some-json-processor There is also pip’s console_script entry-point, you can call this utility as xml2json: $ xml2json -d abdera mydata.xml 15 xmljson Documentation, Release 0.2.0 16 Chapter 7. Simple CLI utility CHAPTER 8 Roadmap • Test cases for Unicode • Support for namespaces and namespace prefixes • Support XML comments 17 xmljson Documentation, Release 0.2.0 18 Chapter 8. Roadmap CHAPTER 9 More information 9.1 Contributing Contributions are welcome, and they are greatly appreciated! Every little bit helps, and credit will always be given. You can contribute in many ways: 9.1.1 Types of Contributions Report Bugs Report bugs at https://github.com/sanand0/xmljson/issues. If you are reporting a bug, please include: • Your operating system name and version. • Any details about your local setup that might be helpful in troubleshooting. • Detailed steps to reproduce the bug. Fix Bugs Look through the GitHub issues for bugs. Anything tagged with “bug” is open to whoever wants to implement it. Implement Features Look through the GitHub issues for features. Anything tagged with “feature” is open to whoever wants to implement it. 19 xmljson Documentation, Release 0.2.0 Write Documentation xmljson could always use more documentation, whether as part of the official xmljson docs, in docstrings, or even on the web in blog posts, articles, and such. Submit Feedback The best way to send feedback is to file an issue at https://github.com/sanand0/xmljson/issues. If you are proposing a feature: • Explain in detail how it would work. • Keep the scope as narrow as possible, to make it easier to implement. • Remember that this is a volunteer-driven project, and that contributions are welcome :) 9.1.2 Get Started! xmljson runs on Python 2.6+ and Python 3+ in any OS. To set up the development environment: 1. Fork the xmljson repo 2. Clone your fork locally: git clone [email protected]:your_user_id/xmljson.git 3. Install your local copy into a virtualenv. If you have virtualenvwrapper installed, this is how you set up your fork for local development: $ mkvirtualenv xmljson $ cd xmljson/ $ python setup.py develop 4. Create