Python: Read/Write to JSON

By Xah Lee. Date: . Last updated: .

The library “json” converts JavaScript JSON format to/from Python nested dictionary/list. Basically, JavaScript array is Python's list, and JavaScript object is Python's dictionary.

For reading/writing to file, use:

Python Object to JSON

Here's example of converting Python object to JSON:

# -*- coding: utf-8 -*-
# python

# python nested dictionary/list to JSON

import json

python_object = ['x3', {'x4': ('8', None, 1.0, 2)}]

print json.dumps(python_object)
# ["x3", {"x4": ["8", null, 1.0, 2]}]

JSON to Python Object

Here's example of converting JSON to Python object:

# -*- coding: utf-8 -*-
# python

# convert JSON to Python nested dictionary/list

import json

json_data = '["x3", {"x4": ["8", null, 1.0, 2]}]'

python_obj = json.loads(json_data)

print python_obj
# [u'x3', {u'x4': [u'8', None, 1.0, 2]}]

Here's example of reading JSON from a file:

# -*- coding: utf-8 -*-
# python

# example of reading JSON from a file

import json
my_data = json.loads(open("xyz.json").read())

print my_data

Pretty Print JSON

You can use the json lib to pretty print nested hash, by giving the argument indent=1.

# -*- coding: utf-8 -*-
# python

import json  # pretty print nested hash

hh = {3:4,5:6, 7:{9:{8:10},11:12}}

print json.dumps(hh,indent=1)

# {
#  "3": 4,
#  "5": 6,
#  "7": {
#   "9": {
#    "8": 10
#   },
#   "11": 12
#  }
# }

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Python by Example

  1. Python Basics
  2. Print Version String
  3. Builtin Help
  4. Quote String
  5. String Operations
  6. String Methods
  7. Format String
  8. True, False
  9. if then else
  10. for, while, Loops
  11. List Basics
  12. Loop Thru List
  13. Map Function to List
  14. List Comprehension
  15. List Methods
  16. Dictionary
  17. Loop Thru Dict
  18. Dict Methods
  19. Function
  20. Class
  21. List Modules
  22. Write a Module
  23. Unicode 🐍

Regex

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Text Processing

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Web

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Misc

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Advanced

  1. Sort
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  3. Tuple vs List
  4. Sets, Union, Intersection
  5. Closure in Python 2
  6. Decorator
  7. Append String in Loop
  8. Timing f timeit
  9. Keyword Arg Default Value Unstable