Write list of dictionaries to file python

The way you will have to follow to write a dict to a file is kind different from the post you have mentioned.

First, you need serialize the object and than you persist it. These are fancy names for "write python objects to a file".

Python has 3 serialization modules included by default that you can use to achieve your objective. They are: pickle, shelve and json. Each one has its own characteristics and the one you have to use is the one which is more suitable to your project. You should check each module documentation to get more on it.

If your data will be only be accessed by python code, you can use shelve, here is an example:

import shelve

my_dict = {"foo":"bar"}

# file to be used
shelf = shelve.open("filename.shlf")

# serializing
shelf["my_dict"] = my_dict

shelf.close() # you must close the shelve file!!!

To retrieve the data you can do:

import shelve

shelf = shelve.open("filename.shlf") # the same filename that you used before, please
my_dict = shelf["my_dict"]
shelf.close()

See that you can treat the shelve object almost the same way you do with a dict.

In this article, we will discuss how to convert a list of dictionaries to JSON in python

Method 1: Using json.dumps()

This function will convert a list of dictionaries to JSON.

Syntax:

json.dumps(dict, indent)

Parameters:  

• dictionary – name of a dictionary which should be converted to JSON object.
• indent – defines the number of units for indentation

Example: Python program to create a list of dictionaries of employee data and convert to JSON

Python3

import json

data = [{"id": ("1", "2", "3"), "name": ("bhanu", "sivanagulu"), 

         "department": ("HR", "IT")},

        {"id": ("4", "5", "6"), "name": ("sai", "poori"),

         "department": ("HR", "IT")},

        {"id": ("7", "8", "9"), "name": ("teja", "gowtam"),

         "department": ("finance", "IT")},

        {"id": ("10", "11", "12"), "name": ("sai", "jyothi"),

         "department": ("business", "IT")},

        {"id": ("13", "14", "15"), "name": ("prudhvi", "nagendram"),

         "department": ("business", "IT")}]

final = json.dumps(data, indent=2)

print(final)

Output:

[
  {
    "id": [
      "1",
      "2",
      "3"
    ],
    "name": [
      "bhanu",
      "sivanagulu"
    ],
    "department": [
      "HR",
      "IT"
    ]
  },
  {
    "id": [
      "4",
      "5",
      "6"
    ],
    "name": [
      "sai",
      "poori"
    ],
    "department": [
      "HR",
      "IT"
    ]
  },
  {
    "id": [
      "7",
      "8",
      "9"
    ],
    "name": [
      "teja",
      "gowtam"
    ],
    "department": [
      "finance",
      "IT"
    ]
  },
  {
    "id": [
      "10",
      "11",
      "12"
    ],
    "name": [
      "sai",
      "jyothi"
    ],
    "department": [
      "business",
      "IT"
    ]
  },
  {
    "id": [
      "13",
      "14",
      "15"
    ],
    "name": [
      "prudhvi",
      "nagendram"
    ],
    "department": [
      "business",
      "IT"
    ]
  }
]

Method 2: Using json.dump()

This will write converted JSON data into a file.

Syntax:

json.dump(dict, file_pointer)

Parameters:  

• dictionary – the name of dictionary which should be converted to JSON object.
• file pointer – pointer of the file opened in write or append mode.

Syntax:

with open("mydata.json", "w") as final:
   json.dump(data, final)

where mydata is the new JSON file. Finally, we have to download the created JSON file

Syntax:

files.download('mydata.json')

Example:

Python3

from google.colab import files

import json

data = [{"id": ("1", "2", "3"), "name": ("bhanu", "sivanagulu"),

         "department": ("HR", "IT")},

        {"id": ("4", "5", "6"), "name": ("sai", "poori"),

         "department": ("HR", "IT")},

        {"id": ("7", "8", "9"), "name": ("teja", "gowtam"),

         "department": ("finance", "IT")},

        {"id": ("10", "11", "12"), "name": ("sai", "jyothi"),

         "department": ("business", "IT")},

        {"id": ("13", "14", "15"), "name": ("prudhvi", "nagendram"),

         "department": ("business", "IT")}]

with open("mydata.json", "w") as final:

    json.dump(data, final)

files.download('mydata.json')

Output:

[{“id”: [“1”, “2”, “3”], “name”: [“bhanu”, “sivanagulu”], “department”: [“HR”, “IT”]}, {“id”: [“4”, “5”, “6”], “name”: [“sai”, “poori”], “department”: [“HR”, “IT”]}, {“id”: [“7”, “8”, “9”], “name”: [“teja”, “gowtam”], “department”: [“finance”, “IT”]}, {“id”: [“10”, “11”, “12”], “name”: [“sai”, “jyothi”], “department”: [“business”, “IT”]}, {“id”: [“13”, “14”, “15”], “name”: [“prudhvi”, “nagendram”], “department”: [“business”, “IT”]}]

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