json.dumps() is a Python function that converts a Python object (like a dictionary, list, or string) into a JSON-formatted string. It is used when you need to serialize data for storage, transmission (e.g., over APIs), or further processing as text.

Key Features:

• Returns a string: The output is a str object, not a file.

• Common use cases: Sending data to web APIs, saving structured data as text, or preparing data for logging.

• Formatting options:

  • indent: Adds pretty-printing (e.g., indent=2 for 2-space indentation).

  • sort_keys: Sorts dictionary keys alphabetically (e.g., sort_keys=True).

  • ensure_ascii: Controls whether non-ASCII characters are escaped (default: True).

  • separators: Customizes separators between items and keys (e.g., separators=(',', ':')).

Example:

import json

data = {"name": "Alice", "age": 30, "skills": ["Python", "SQL"]}
json_string = json.dumps(data, indent=2, sort_keys=True)
print(json_string)

Output:

{
  "age": 30,
  "name": "Alice",
  "skills": [
    "Python",
    "SQL"
  ]
}

💡 Note: Use json.dump() to write directly to a file. json.dumps() returns a string, which can then be written to a file manually if needed.