coding-mentor-agent/kb/python-course-kb-practical-python/wiki/exercises/2-2-dictionaries-as-a-data-structure.md

id, source_exercise_id, title, section, source_path, source_repo, source_commit, student_visible_solution, has_private_solution, skip

id	source_exercise_id	title	section	source_path	source_repo	source_commit	student_visible_solution	has_private_solution	skip
practical-python-2.2	2.2	Dictionaries as a data structure	2.1 Datatypes and Data structures	02_Working_with_data/01_Datatypes.md	https://github.com/dabeaz-course/practical-python	93dca856b41c61a0a0f85ae334116e4c125629ea	false	false	false

Exercise 2.2: Dictionaries as a data structure

Source: Practical Python Programming, 02_Working_with_data/01_Datatypes.md.

Exercise 2.2: Dictionaries as a data structure

An alternative to a tuple is to create a dictionary instead.

>>> d = {
        'name' : row[0],
        'shares' : int(row[1]),
        'price'  : float(row[2])
    }
>>> d
{'name': 'AA', 'shares': 100, 'price': 32.2 }
>>>

Calculate the total cost of this holding:

>>> cost = d['shares'] * d['price']
>>> cost
3220.0000000000005
>>>

Compare this example with the same calculation involving tuples above. Change the number of shares to 75.

>>> d['shares'] = 75
>>> d
{'name': 'AA', 'shares': 75, 'price': 32.2 }
>>>

Unlike tuples, dictionaries can be freely modified. Add some attributes:

>>> d['date'] = (6, 11, 2007)
>>> d['account'] = 12345
>>> d
{'name': 'AA', 'shares': 75, 'price':32.2, 'date': (6, 11, 2007), 'account': 12345}
>>>

关联来源

• summaries/01_Datatypes