mirror of
https://github.com/kennethreitz/python-guide.git
synced 2026-06-05 23:00:18 +00:00
Matthew Lewis
87 lines
2.3 KiB
ReStructuredText
87 lines
2.3 KiB
ReStructuredText
JSON
|
|
====
|
|
|
|
The `json <https://docs.python.org/2/library/json.html>`_ library can parse JSON from strings or files. The library parses JSON into a Python dictionary or list. It can also convert Python dictionaries or lists into JSON strings.
|
|
|
|
Parsing JSON
|
|
------------
|
|
|
|
Take the following string containing JSON data:
|
|
|
|
.. code-block:: python
|
|
|
|
json_string = '{"first_name": "Guido", "last_name":"Rossum"}'
|
|
|
|
It can be parsed like this:
|
|
|
|
.. code-block:: python
|
|
|
|
import json
|
|
parsed_json = json.loads(json_string)
|
|
|
|
and can now be used as a normal dictionary:
|
|
|
|
.. code-block:: python
|
|
|
|
print(parsed_json['first_name'])
|
|
"Guido"
|
|
|
|
You can also convert the following to JSON:
|
|
|
|
.. code-block:: python
|
|
|
|
d = {
|
|
'first_name': 'Guido',
|
|
'second_name': 'Rossum',
|
|
'titles': ['BDFL', 'Developer'],
|
|
}
|
|
|
|
print(json.dumps(d))
|
|
'{"first_name": "Guido", "last_name": "Rossum", "titles": ["BDFL", "Developer"]}'
|
|
|
|
Working with File Objects
|
|
-------------------------
|
|
|
|
We can also load a JSON file by using ``json.load`` instead of ``json.loads``:
|
|
|
|
.. code-block:: python
|
|
|
|
import json
|
|
|
|
with file('path/to/file.json') as f:
|
|
loaded_json = json.load(f)
|
|
|
|
print(loaded_json) # {'first_name': 'Ada', 'last_name': 'Lovelace'}
|
|
|
|
Here's an example of writing directly to a file by using ``json.dump`` instead of ``json.dumps``:
|
|
|
|
.. code-block:: python
|
|
|
|
import json
|
|
|
|
my_data = {
|
|
'name': 'Alan Turing',
|
|
'played_by': 'Benedict Cumberbatch'
|
|
}
|
|
|
|
with file('path/to/file.json', 'w') as f:
|
|
json.dump(my_data, f)
|
|
|
|
``path/to/file.json`` now contains a JSON representation of the my_data dictionary.
|
|
|
|
|
|
simplejson
|
|
----------
|
|
|
|
The JSON library was added to Python in version 2.6. If you're using an earlier version of Python, the `simplejson <https://simplejson.readthedocs.org/en/latest/>`_ library is available via PyPI.
|
|
|
|
simplejson mimics the json standard library. It is available so that developers that use older versions of Python can use the latest features available in the json lib.
|
|
|
|
You can start using simplejson when the json library is not available by importing simplejson under a different name:
|
|
|
|
.. code-block:: python
|
|
|
|
import simplejson as json
|
|
|
|
After importing simplejson as json, the above examples will all work as if you were using the standard json library.
|