How to add list to JSON object in Python

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JSON is a syntax for storing and exchanging data.

JSON is text, written with JavaScript object notation.


JSON in Python

Python has a built-in package called json, which can be used to work with JSON data.

Example

Import the json module:      import json


Parse JSON - Convert from JSON to Python

If you have a JSON string, you can parse it by using the json.loads() method.

The result will be a Python dictionary.

Example

Convert from JSON to Python:  import json

# some JSON:
x = '{ "name":"John", "age":30, "city":"New York"}'

# parse x:
y = json.loads(x)

# the result is a Python dictionary:
print(y["age"])Try it Yourself »


Convert from Python to JSON

If you have a Python object, you can convert it into a JSON string by using the json.dumps() method.

Example

Convert from Python to JSON:  import json

# a Python object (dict):
x = {
"name": "John",
"age": 30,
"city": "New York"
}

# convert into JSON:
y = json.dumps(x)

# the result is a JSON string:
 print(y)Try it Yourself »



You can convert Python objects of the following types, into JSON strings:

  • dict
  • list
  • tuple
  • string
  • int
  • float
  • True
  • False
  • None

Example

Convert Python objects into JSON strings, and print the values:  import json

print(json.dumps({"name": "John", "age": 30}))
print(json.dumps(["apple", "bananas"]))
print(json.dumps(("apple", "bananas")))
 print(json.dumps("hello"))
print(json.dumps(42))
print(json.dumps(31.76))
print(json.dumps(True))
print(json.dumps(False))
print(json.dumps(None))Try it Yourself »


When you convert from Python to JSON, Python objects are converted into the JSON (JavaScript) equivalent: Python JSON dict Object list Array tuple Array str String int Number float Number True true False false None null


Example

Convert a Python object containing all the legal data types:  import json

x = {
"name": "John",
"age": 30,
"married": True,
"divorced": False,
"children": ("Ann","Billy"),
"pets": None,
"cars": [
{"model": "BMW 230", "mpg": 27.5},
{"model": "Ford Edge", "mpg": 24.1}
]
 }

print(json.dumps(x))
Try it Yourself »


Format the Result

The example above prints a JSON string, but it is not very easy to read, with no indentations and line breaks.

The json.dumps() method has parameters to make it easier to read the result:

Example

Use the indent parameter to define the numbers of indents:      json.dumps(x, indent=4)
Try it Yourself »

You can also define the separators, default value is (", ", ": "), which means using a comma and a space to separate each object, and a colon and a space to separate keys from values:

Example

Use the separators parameter to change the default separator:      json.dumps(x, indent=4, separators=(". ", " = "))
Try it Yourself »


Order the Result

The json.dumps() method has parameters to order the keys in the result:

Example

Use the sort_keys parameter to specify if the result should be sorted or not:      json.dumps(x, indent=4, sort_keys=True)
Try it Yourself »


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