JSON in Python (P1)

Tram Ho

4 years ago

1. What is JSON?

JSON is a data format that uses plain text, JSON format uses key-value pairs for the data to use. JSON was originally developed for use in JavaScript applications. The JSON term itself stands for JavaScript Object Notation. However, since JSON is a data format, it can be used by any language without limitation with JavaScript.

2. JSON in Python

Python has a built-in caller called json that can be used to work with JSON data.

import json

1 2	import json

1. Convert JSON in Python

Use the json.loads() function to convert a JSON string to Dictionary

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"])

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"])

2. Convert the Python object to JSON

Use the json.dumps() function to convert a Python Object into a JSON string

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)

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)

The list of objects can be converted to a JSON string

dict
list
tuple
string
int
float
True
False
None

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))

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))

Object conversion table between Python and JSON

Python	JSON
dict	Object
list	Array
tuple	Array
str	String
int	Number
float	Number
True	true
False	false
None	null

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))

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))

3. Format display

For a nice display, it is easier to see json.dumps() provides an additional indent parameter to format the indent number (1 indent equals 1 space)

json.dumps(x, indent=4)

1 2	json.dumps(x, indent=4)

4. Arrange the key

By default JSON will display the keys out of order. To sort keys, json.dumps() provides the sort_keys parameter

json.dumps(x, indent=4, sort_keys=True)

1 2	json.dumps(x, indent=4, sort_keys=True)

3. Conclusion

The json module in Python also integrates many other features in the above methods. The next part I will provide more for you. Source: https://www.w3schools.com/python/python_json.asp

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