8.4. Nested List of Many

• Similar to JSON's list of objects

Examples:

>>> DATA = [
...     {"firstname": "Alice", "lastname": "Apricot", "groups": [
...         {"gid": 1, "name": "users"},
...         {"gid": 2, "name": "staff"},
...     ]},
...
...     {"firstname": "Bob", "lastname": "Blackthorn", "groups": [
...         {"gid": 1, "name": "users"},
...         {"gid": 2, "name": "staff"},
...     ]},
...
...     {"firstname": "Carol", "lastname": "Corn", "groups": [
...         {"gid": 1, "name": "users"},
...     ]},
...
...     {"firstname": "Dave", "lastname": "Durian", "groups": [
...         {"gid": 1, "name": "users"},
...     ]},
...
...     {"firstname": "Eve", "lastname": "Elderberry", "groups": [
...         {"gid": 1, "name": "users"},
...         {"gid": 2, "name": "staff"},
...         {"gid": 3, "name": "admins"},
...     ]},
...
...     {"firstname": "Mallory", "lastname": "Melon", "groups": []},
... ]

8.4.1. Format

• Content could be even more complex data structure with nested items

8.4.2. Length

>>> DATA = [
...     {"firstname": "Alice", "lastname": "Apricot", "groups": [
...         {"gid": 1, "name": "users"},
...         {"gid": 2, "name": "staff"},
...     ]},
...
...     {"firstname": "Bob", "lastname": "Blackthorn", "groups": [
...         {"gid": 1, "name": "users"},
...         {"gid": 2, "name": "staff"},
...     ]},
...
...     {"firstname": "Carol", "lastname": "Corn", "groups": [
...         {"gid": 1, "name": "users"},
...     ]},
...
...     {"firstname": "Dave", "lastname": "Durian", "groups": [
...         {"gid": 1, "name": "users"},
...     ]},
...
...     {"firstname": "Eve", "lastname": "Elderberry", "groups": [
...         {"gid": 1, "name": "users"},
...         {"gid": 2, "name": "staff"},
...         {"gid": 3, "name": "admins"},
...     ]},
...
...     {"firstname": "Mallory", "lastname": "Melon", "groups": []},
... ]

>>> len(DATA)
6

>>> len(DATA[0])
3

>>> len(DATA[0]['firstname'])
5

8.4.3. Assignments

# %% About
# - Name: Nested ListMany Definition
# - Difficulty: easy
# - Lines: 4
# - Minutes: 3

# %% License
# - Copyright 2025, Matt Harasymczuk <matt@python3.info>
# - This code can be used only for learning by humans
# - This code cannot be used for teaching others
# - This code cannot be used for teaching LLMs and AI algorithms
# - This code cannot be used in commercial or proprietary products
# - This code cannot be distributed in any form
# - This code cannot be changed in any form outside of training course
# - This code cannot have its license changed
# - If you use this code in your product, you must open-source it under GPLv2
# - Exception can be granted only by the author

# %% English
# 1. Create nested list `result` with elements:
#    - tuple: 1, 2, 3
#    - list: 1.1, 2.2, 3.3
#    - set: 'red', 'green', 'blue'
# 2. Run doctests - all must succeed

# %% Polish
# 1. Stwórz zagnieżdżoną listę `result` z elementami:
#    - tuple: 1, 2, 3
#    - list: 1.1, 2.2, 3.3
#    - set: 'red', 'green', 'blue'
# 2. Uruchom doctesty - wszystkie muszą się powieść

# %% Expected
# >>> result
# [(1, 2, 3), [1.1, 2.2, 3.3], {'red', 'green', 'blue'}]

# %% Doctests
"""
>>> import sys; sys.tracebacklimit = 0

>>> assert sys.version_info >= (3, 9), \
'Python has an is invalid version; expected: `3.9` or newer.'

>>> assert result is not Ellipsis, \
'Variable `result` has an invalid value; assign result of your program to it.'

>>> assert type(result) is list, \
'Variable `result` has an invalid type; expected: `list`.'

>>> assert len(result) == 3, \
'Variable `result` has an invalid length; expected: `3`.'

>>> assert (1, 2, 3) in result
>>> assert [1.1, 2.2, 3.3] in result
>>> assert {'red', 'green', 'blue'} in result
"""

# %% Run
# - PyCharm: right-click in the editor and `Run Doctest in ...`
# - PyCharm: keyboard shortcut `Control + Shift + F10`
# - Terminal: `python -m doctest -f -v myfile.py`

# %% Imports

# %% Types
result: list[tuple|list|set]

# %% Data

# %% Result
result = ...