(Chilkat2-Python) JSON Paths

Demonstrates using "Chilkat JSON Paths" to access parts of a JSON document, or to iterate over parts.

This example uses the following JSON document:

{
    "nestedArray" : [
			[
				[1,2,3],
				[4,5,6],
				[7,8,9,10]
			],
			[
				[11,12,13],
				[14,15,16],
				[17,18,19,20]
			],
			[
				[21,22,23],
				[24,25,26],
				[27,28,29,30],
				[31,32,33,34,35,36]
			]
		],

	"nestedObject" : {
		"aaa" : {
			"bb1" : {
				"cc1" : "c1Value",
				"cc2" : "c2Value",
				"cc3" : "c3Value"
			},
			"bb2" : {
				"dd1" : "d1Value",
				"dd2" : "d2Value",
				"dd3" : "d3Value"
			}
		}
	},

	"mixture" : {
		"arrayA" : [  
			{ "fruit": "apple", "animal": "horse", "job": "fireman", "colors": ["red","blue","green"] },
			{ "fruit": "pear", "animal": "plankton", "job": "waiter", "colors": ["yellow","orange","purple"] },
			{ "fruit": "kiwi", "animal": "echidna", "job": "astronaut", "colors": ["magenta","tan","pink"] }
			]
	},


        "name.with.dots" : { "grain" : "oats" }

	
}

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat2 Python Downloads install with pip pip3 install chilkat2 or download... Python Module for Windows, Linux, Alpine Linux, MacOS

import sys
import chilkat2

success = False

json = chilkat2.JsonObject()
json.EmitCompact = False

# Assume the file contains the data as shown above..
success = json.LoadFile("qa_data/json/pathSample.json")
if (success == False):
    print(json.LastErrorText)
    sys.exit()

# First, let's get the value of "cc1"
# The path to this value is: nestedObject.aaa.bb1.cc1
print(json.StringOf("nestedObject.aaa.bb1.cc1"))

# Now let's get number 18 from the nestedArray.
# It is located at nestedArray[1][2][1]
# (remember: Indexing is 0-based)
print("This should be 18: " + str(json.IntOf("nestedArray[1][2][1]")))

# We can do the same thing in a more roundabout way using the 
# I, J, and K properties.  (The I,J,K properties will be convenient
# for iterating over arrays, as we'll see later.)
json.I = 1
json.J = 2
json.K = 1
print("This should be 18: " + str(json.IntOf("nestedArray[i][j][k]")))

# Let's iterate over the array containing the numbers 17, 18, 19, 20.
# First, use the SizeOfArray method to get the array size:
sz = json.SizeOfArray("nestedArray[1][2]")
# The size should be 4.
print("size of array = " + str(sz) + " (should equal 4)")

# Now iterate...

for i in range(0,sz):
    json.I = i
    print(str(json.IntOf("nestedArray[1][2][i]")))

# Let's use a triple-nested loop to iterate over the nestedArray:

# szI should equal 1.
szI = json.SizeOfArray("nestedArray")
for i in range(0,szI):
    json.I = i

    szJ = json.SizeOfArray("nestedArray[i]")
    for j in range(0,szJ):
        json.J = j

        szK = json.SizeOfArray("nestedArray[i][j]")
        for k in range(0,szK):
            json.K = k

            print(str(json.IntOf("nestedArray[i][j][k]")))

# Now let's examine how to navigate to JSON objects contained within JSON arrays.
# This line of code gets the value "kiwi" contained within "mixture"
print(json.StringOf("mixture.arrayA[2].fruit"))

# This line of code gets the color "yellow"
print(json.StringOf("mixture.arrayA[1].colors[0]"))

# Getting an object at a path:
# This gets the 2nd object in "arrayA"

obj2 = chilkat2.JsonObject()
json.ObjectOf2("mixture.arrayA[1]",obj2)

# This object's "animal" should be "plankton"
print(obj2.StringOf("animal"))

# Note that paths are relative to the object, not the absolute root of the JSON document.
# Starting from obj2, "purple" is at "colors[2]"
print(obj2.StringOf("colors[2]"))

# Getting an array at a path:
# This gets the array containing the colors red, green, blue:

arr1 = chilkat2.JsonArray()
json.ArrayOf2("mixture.arrayA[0].colors",arr1)

szArr1 = arr1.Size
for i in range(0,szArr1):
    print(str(i) + ": " + arr1.StringAt(i))

# The Chilkat JSON path uses ".", "[", and "]" chars for separators.  When a name
# contains one of these chars, use double-quotes in the path:
print(json.StringOf("\"name.with.dots\".grain"))