The way to access nested JSON objects in Python is to first clarify the structure and then index layer by layer. First, confirm the hierarchical relationship of JSON, such as a dictionary nested dictionary or list; then use dictionary keys and list index to access layer by layer, such as data "details"["zip"] to obtain zip encoding, data "details"[0] to obtain the first hobby; to avoid KeyError and IndexError, the default value can be set by the .get() method, or the encapsulation function safe_get can be used to achieve secure access; for complex structures, recursively search or use third-party libraries such as jmespath to handle.
It is not difficult to access nested JSON objects in Python. The key is to figure out the structure and then search down one by one. JSON is essentially very similar to Python's dictionary and list structure, so as long as you understand the hierarchical relationship, you can easily get the value.

First look at the structure: confirm how your JSON is nested
After getting a JSON data, the first step is to see what structure it is. For example, the following example:
{ "name": "Alice", "details": { "age": 30, "location": { "city": "Shanghai", "zip": "200000" }, "hobbies": ["reading", "cycling"] } }
This is a typical nested structure:

-
details
is a dictionary -
location
is another dictionary nested indetails
-
hobbies
is a list
If you don't know the structure, you can first use print(json_data)
or online formatting tools to see the hierarchical relationship.
Layer-by-layer access using dictionary and list index
Python handles this structure very simple, just "drill in" layer by layer.

For example, to obtain the zip code of the city where Alice is located, you can write it like this:
zip_code = data["details"]["location"]["zip"]
If it is a list, such as hobbies, you want to get your first hobbies:
first_hobby = data["details"]["hobbies"][0]
A few points to note:
- Does the field exist? If you are not sure, it is recommended to use
.get()
to avoid errors - Is there an element in the list? It is best to judge the length before visiting
- When the nesting is too deep, remember to do it step by step and don't write too long expressions at once.
Secure access tips: Avoid KeyError and IndexError
Direct access using []
can sometimes error, especially if the field may not exist or the list is empty. At this time, you can use the .get()
method to match the default value:
city ??= data.get("details", {}).get("location", {}).get("city")
If no intermediate step is found, None
will be returned (or the default value you specified) and will not crash directly.
It can also be encapsulated into a small function:
def safe_get(data, *keys): for key in keys: if isinstance(data, dict) and key in data: data = data[key] else: return None return data
Call method:
city ??= safe_get(data, "details", "location", "city")
What if the structure is complicated?
Some JSONs are particularly deep nested, or the field names are dynamically generated, and even array nested objects. You can consider this at this time:
- Find specific fields using recursive traversal
- Third-party libraries such as
jmespath
to do advanced query
But in most daily scenarios, the above method is enough.
Basically that's it. The core is to see the structure clearly, access it layer by layer, and pay attention to safely dealing with exceptions.
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