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Why use jsonpath?

Just like why you use xpath, jsonpath is inspired by xpath. A powerful json data extraction tool. Allows users to extract the corresponding json data without writing a script.

Syntax of jsonpath

What can jsonpath do to retrieve data in two modes:

Separated by points

$.store.book [0] .title

$.store.book [*] .title # can get the book value

Separated by square brackets

$['store'] [' book'] [0] ['title']

For input. Path, the inner middle path will always use the more generic bracket pattern. (I guess because jsonpath is dict in python, the access method happens to be in square brackets.)

[start:end:step] mode is also supported

@ symbolic expression: can be used to represent either length or name.

$.store.book [(@ .length-1)] .title # gets the title of the last book

$.store.book [? (@ .price < 10)] .title # fetches the title of a book whose price is less than 10

Jsonpath parsing

Next, let's talk about a very powerful and convenient jsonpath dedicated to json parsing to solve the long-standing problem of deep path!

Install the dependency package first

Pip install jsonpath

To learn jsonpath, we have to mention xpath, and the grammar between the two is similar.

XpathJSONPath description / $follows node. @ current node /. Or [] takes the child node.. nCompact a takes the parent node JsonPath does not support / /.. The relative node is to select all the conditions that meet the conditions regardless of the location.

| | * | match all element nodes |

[] | [] | iterator tag (you can do simple iterative operations, such as array subscript, select values according to content, etc.)

& # 124 | [,] | support multiple selections in iterators

[] |? () | filter operation is supported

Ncanapa | () | support expression evaluation

() | Nampa | grouping, which is not supported by JsonPath

Use the example

$is the root node of the lookup, and the passing parameter is the dict type of python. It returns a list result when it is found, and False when the lookup fails.

Import jsonpathresult = {"code": 0, "data": [{"age": 20, "create_time": "2021-09-15", "id": 1, "mail": "2833479@qq.com", "name": "yoyo", "sex": "M"} {"age": 21, "create_time": "2021-09-16", "id": 2, "mail": "12344@qq.com", "name": "yoyo111", "sex": "M"}], "msg": "success!"} msg = jsonpath.jsonpath (result '$.msg') print (msg) # output result names = jsonpath.jsonpath (result,'$.. name') print (names) # output result ['yoyo',' yoyo111'] no = jsonpath.jsonpath (result,'$.. yoyo') print (no) # No result found is False

In this way, the value can be taken regardless of the hierarchy.

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