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- Metadata-Version: 2.0
- Name: jmespath
- Version: 0.9.3
- Summary: JSON Matching Expressions
- Home-page: https://github.com/jmespath/jmespath.py
- Author: James Saryerwinnie
- Author-email: js@jamesls.com
- License: MIT
- Platform: UNKNOWN
- Classifier: Development Status :: 5 - Production/Stable
- Classifier: Intended Audience :: Developers
- Classifier: Natural Language :: English
- Classifier: License :: OSI Approved :: MIT License
- Classifier: Programming Language :: Python
- Classifier: Programming Language :: Python :: 2.6
- Classifier: Programming Language :: Python :: 2.7
- Classifier: Programming Language :: Python :: 3
- Classifier: Programming Language :: Python :: 3.3
- Classifier: Programming Language :: Python :: 3.4
- Classifier: Programming Language :: Python :: 3.5
- Classifier: Programming Language :: Python :: 3.6
- Classifier: Programming Language :: Python :: Implementation :: CPython
- Classifier: Programming Language :: Python :: Implementation :: PyPy
-
- JMESPath
- ========
-
-
- .. image:: https://badges.gitter.im/Join Chat.svg
- :target: https://gitter.im/jmespath/chat
-
-
- .. image:: https://secure.travis-ci.org/jmespath/jmespath.py.png?branch=develop
- :target: http://travis-ci.org/jmespath/jmespath.py
-
-
- .. image:: https://codecov.io/github/jmespath/jmespath.py/coverage.svg?branch=develop
- :target: https://codecov.io/github/jmespath/jmespath.py?branch=develop
-
-
- JMESPath (pronounced "james path") allows you to declaratively specify how to
- extract elements from a JSON document.
-
- For example, given this document::
-
- {"foo": {"bar": "baz"}}
-
- The jmespath expression ``foo.bar`` will return "baz".
-
- JMESPath also supports:
-
- Referencing elements in a list. Given the data::
-
- {"foo": {"bar": ["one", "two"]}}
-
- The expression: ``foo.bar[0]`` will return "one".
- You can also reference all the items in a list using the ``*``
- syntax::
-
- {"foo": {"bar": [{"name": "one"}, {"name": "two"}]}}
-
- The expression: ``foo.bar[*].name`` will return ["one", "two"].
- Negative indexing is also supported (-1 refers to the last element
- in the list). Given the data above, the expression
- ``foo.bar[-1].name`` will return "two".
-
- The ``*`` can also be used for hash types::
-
- {"foo": {"bar": {"name": "one"}, "baz": {"name": "two"}}}
-
- The expression: ``foo.*.name`` will return ["one", "two"].
-
-
- API
- ===
-
- The ``jmespath.py`` library has two functions
- that operate on python data structures. You can use ``search``
- and give it the jmespath expression and the data:
-
- .. code:: python
-
- >>> import jmespath
- >>> path = jmespath.search('foo.bar', {'foo': {'bar': 'baz'}})
- 'baz'
-
- Similar to the ``re`` module, you can use the ``compile`` function
- to compile the JMESPath expression and use this parsed expression
- to perform repeated searches:
-
- .. code:: python
-
- >>> import jmespath
- >>> expression = jmespath.compile('foo.bar')
- >>> expression.search({'foo': {'bar': 'baz'}})
- 'baz'
- >>> expression.search({'foo': {'bar': 'other'}})
- 'other'
-
- This is useful if you're going to use the same jmespath expression to
- search multiple documents. This avoids having to reparse the
- JMESPath expression each time you search a new document.
-
- Options
- -------
-
- You can provide an instance of ``jmespath.Options`` to control how
- a JMESPath expression is evaluated. The most common scenario for
- using an ``Options`` instance is if you want to have ordered output
- of your dict keys. To do this you can use either of these options:
-
- .. code:: python
-
- >>> import jmespath
- >>> jmespath.search('{a: a, b: b},
- ... mydata,
- ... jmespath.Options(dict_cls=collections.OrderedDict))
-
-
- >>> import jmespath
- >>> parsed = jmespath.compile('{a: a, b: b}')
- >>> parsed.search('{a: a, b: b},
- ... mydata,
- ... jmespath.Options(dict_cls=collections.OrderedDict))
-
-
- Custom Functions
- ~~~~~~~~~~~~~~~~
-
- The JMESPath language has numerous
- `built-in functions
- <http://jmespath.org/specification.html#built-in-functions>`__, but it is
- also possible to add your own custom functions. Keep in mind that
- custom function support in jmespath.py is experimental and the API may
- change based on feedback.
-
- **If you have a custom function that you've found useful, consider submitting
- it to jmespath.site and propose that it be added to the JMESPath language.**
- You can submit proposals
- `here <https://github.com/jmespath/jmespath.site/issues>`__.
-
- To create custom functions:
-
- * Create a subclass of ``jmespath.functions.Functions``.
- * Create a method with the name ``_func_<your function name>``.
- * Apply the ``jmespath.functions.signature`` decorator that indicates
- the expected types of the function arguments.
- * Provide an instance of your subclass in a ``jmespath.Options`` object.
-
- Below are a few examples:
-
- .. code:: python
-
- import jmespath
- from jmespath import functions
-
- # 1. Create a subclass of functions.Functions.
- # The function.Functions base class has logic
- # that introspects all of its methods and automatically
- # registers your custom functions in its function table.
- class CustomFunctions(functions.Functions):
-
- # 2 and 3. Create a function that starts with _func_
- # and decorate it with @signature which indicates its
- # expected types.
- # In this example, we're creating a jmespath function
- # called "unique_letters" that accepts a single argument
- # with an expected type "string".
- @functions.signature({'types': ['string']})
- def _func_unique_letters(self, s):
- # Given a string s, return a sorted
- # string of unique letters: 'ccbbadd' -> 'abcd'
- return ''.join(sorted(set(s)))
-
- # Here's another example. This is creating
- # a jmespath function called "my_add" that expects
- # two arguments, both of which should be of type number.
- @functions.signature({'types': ['number']}, {'types': ['number']})
- def _func_my_add(self, x, y):
- return x + y
-
- # 4. Provide an instance of your subclass in a Options object.
- options = jmespath.Options(custom_functions=CustomFunctions())
-
- # Provide this value to jmespath.search:
- # This will print 3
- print(
- jmespath.search(
- 'my_add(`1`, `2`)', {}, options=options)
- )
-
- # This will print "abcd"
- print(
- jmespath.search(
- 'foo.bar | unique_letters(@)',
- {'foo': {'bar': 'ccbbadd'}},
- options=options)
- )
-
- Again, if you come up with useful functions that you think make
- sense in the JMESPath language (and make sense to implement in all
- JMESPath libraries, not just python), please let us know at
- `jmespath.site <https://github.com/jmespath/jmespath.site/issues>`__.
-
-
- Specification
- =============
-
- If you'd like to learn more about the JMESPath language, you can check out
- the `JMESPath tutorial <http://jmespath.org/tutorial.html>`__. Also check
- out the `JMESPath examples page <http://jmespath.org/examples.html>`__ for
- examples of more complex jmespath queries.
-
- The grammar is specified using ABNF, as described in
- `RFC4234 <http://www.ietf.org/rfc/rfc4234.txt>`_.
- You can find the most up to date
- `grammar for JMESPath here <http://jmespath.org/specification.html#grammar>`__.
-
- You can read the full
- `JMESPath specification here <http://jmespath.org/specification.html>`__.
-
-
- Testing
- =======
-
- In addition to the unit tests for the jmespath modules,
- there is a ``tests/compliance`` directory that contains
- .json files with test cases. This allows other implementations
- to verify they are producing the correct output. Each json
- file is grouped by feature.
-
-
- Discuss
- =======
-
- Join us on our `Gitter channel <https://gitter.im/jmespath/chat>`__
- if you want to chat or if you have any questions.
-
-
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