Introduction to JSON PATH

JSON (JavaScript Object Notation) is a lightweight data-interchange format that’s easy to read, write, parse, and generate. When working with complex JSON—nested objects, arrays, and mixed data types—you need a concise way to extract specific values. Enter JSONPath, a query language inspired by XPath for XML. JSONPath provides a simple, declarative syntax to traverse and filter JSON structures. In this guide, we’ll explore:

Basic JSONPath syntax
Common operators and filters
Practical Python examples with jsonpath-ng

1. Basic JSONPath Syntax

Consider the following sample JSON document:

{
  "store": {
    "book": [
      { "category": "reference", "author": "Nigel Rees",     "title": "Sayings of the Century",      "price": 8.95 },
      { "category": "fiction",   "author": "Evelyn Waugh",   "title": "Sword of Honour",            "price": 12.99 },
      { "category": "fiction",   "author": "Herman Melville","title": "Moby Dick",                  "isbn": "0-553-21311-3", "price": 8.99 },
      { "category": "fiction",   "author": "J. R. R. Tolkien","title": "The Lord of the Rings",     "isbn": "0-395-19395-8", "price": 22.99 }
    ],
    "bicycle": { "color": "red", "price": 19.95 }
  }
}

Key JSONPath tokens:

$ : the root object
. or [] : child access
* : wildcard match (all elements)
.. : recursive descent

Examples:

$.store.book
→ Returns the array of all books.
$.store.book[0].author
→ "Nigel Rees"
$..price
→ All price values in the document.
$.store.book[?(@.price < 10)]
→ Books with a price less than 10.

JSONPath expressions are case-sensitive. Always match the exact key names when querying.

2. Common Operators and Filters

JSONPath offers a variety of operators for powerful data selection. Below is a quick reference table:

Operator	Description	Example
`*`	Wildcard: matches all child members	`$.store.*`
`..`	Recursive descent through all object levels	`$..author`
`[index]`	Array index access	`$.store.book[2]`
`[start:end]`	Slicing an array	`$.store.book[0:2]`
`[?(@.key <op> value)]`	Filter expression	`$.store.book[?(@.price > 10)]`

Filter operators include:

<, <=, >, >=, ==, !=
Boolean AND/OR (&&, ||)

Ensure your filter syntax is valid. A misplaced parenthesis or comparison operator can lead to no results or errors.

3. Python Examples with `jsonpath-ng`

Follow these steps to query JSON with Python:

Install the library:
pip install jsonpath-ng

Use the following script:

import json
from jsonpath_ng import parse

data = {
    "store": {
        "book": [
            {"category": "reference", "author": "Nigel Rees",      "title": "Sayings of the Century",      "price": 8.95},
            {"category": "fiction",   "author": "Evelyn Waugh",    "title": "Sword of Honour",            "price": 12.99},
            {"category": "fiction",   "author": "Herman Melville","title": "Moby Dick",                  "isbn": "0-553-21311-3", "price": 8.99},
            {"category": "fiction",   "author": "J. R. R. Tolkien","title": "The Lord of the Rings",     "isbn": "0-395-19395-8", "price": 22.99}
        ],
        "bicycle": {"color": "red", "price": 19.95}
    }
}

# Parse and evaluate a JSONPath expression
jsonpath_expr = parse('$.store.book[?(@.price < 10)].title')
matches = jsonpath_expr.find(data)

# Extract and print titles
titles = [match.value for match in matches]
print(titles)

Expected output:

['Sayings of the Century', 'Moby Dick']

Lesson

Introduction to JSON PATH

1. Basic JSONPath Syntax

2. Common Operators and Filters

3. Python Examples with `jsonpath-ng`

Further Reading and References

Watch Video

Practice Lab

​1. Basic JSONPath Syntax

​2. Common Operators and Filters

​3. Python Examples with jsonpath-ng

​Further Reading and References

Watch Video

Practice Lab

1. Basic JSONPath Syntax

2. Common Operators and Filters

3. Python Examples with `jsonpath-ng`

Further Reading and References