Accessing Nested Objects in Python JSON: Dot Notation vs Bracket Notation

Both Code 1 and Code 2 can be used to query the value of 'site2' in myObj_1 because 'sites' is a nested object within myObj_1 and can be accessed either using dot notation (Code 1) or bracket notation (Code 2). Both notations are valid in Python to access properties of an object.

Code 1: Dot Notation

x = myObj_1.sites.site2

Code 2: Bracket Notation

x = myObj_1.sites['site2']

Explanation

• Dot Notation: This notation is used when the property name is a valid Python identifier (no spaces or special characters). You access the nested object 'sites' using the dot operator (.) and then access the 'site2' property within it using another dot operator.
• Bracket Notation: This notation is more flexible and can be used with any property name, including those that are not valid Python identifiers. You access the nested object 'sites' using the dot operator and then use square brackets ([ ]) with the property name 'site2' as a string inside.

Choosing the Right Notation

While both notations work, dot notation is generally preferred for readability when property names are valid Python identifiers. However, bracket notation is useful for cases where property names contain special characters or spaces, or when you need to dynamically access properties based on variables.

Example JSON

myObj_1 = {
    'name': 'runoob',
    'alexa': 10000,
    'sites': {
        'site1': 'www.runoob.com',
        'site2': 'm.runoob.com',
        'site3': 'c.runoob.com'
    }
}