Nested Collections
beginner10 min readLesson 19 of 169
Lists of dicts, dicts with lists — the shape of real data.
Containers nest — lists inside dicts, dicts in lists — and that combination is how real data looks:
students = [
{"name": "Minh", "grades": [8, 9, 7]},
{"name": "Lan", "grades": [10, 9]},
]
students[0]["name"] # 'Minh'
students[1]["grades"][-1] # 9
students[0]["grades"].append(6)
Read nested access inside-out, one bracket at a time. When it gets confusing, print the intermediate value:
first = students[0]
print(first) # see the whole dict before digging deeper
Nested containers are the bridge to everything ahead: files (Module 9 saves them as JSON), modules (Module 10 groups functions), and every real dataset you will ever process.