coding-mentor-agent/kb/python-course-kb-practical-python/wiki/exercises/7-4-argument-pass-through.md

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id	source_exercise_id	title	section	source_path	source_repo	source_commit	student_visible_solution	has_private_solution	skip
practical-python-7.4	7.4	Argument pass-through	7.1 Variable Arguments	07_Advanced_Topics/01_Variable_arguments.md	https://github.com/dabeaz-course/practical-python	93dca856b41c61a0a0f85ae334116e4c125629ea	false	true	false

Exercise 7.4: Argument pass-through

Source: Practical Python Programming, 07_Advanced_Topics/01_Variable_arguments.md.

Exercise 7.4: Argument pass-through

The fileparse.parse_csv() function has some options for changing the file delimiter and for error reporting. Maybe you'd like to expose those options to the read_portfolio() function above. Make this change:

def read_portfolio(filename, **opts):
    '''
    Read a stock portfolio file into a list of dictionaries with keys
    name, shares, and price.
    '''
    with open(filename) as lines:
        portdicts = fileparse.parse_csv(lines,
                                        select=['name','shares','price'],
                                        types=[str,int,float],
                                        **opts)

    portfolio = [ Stock(**d) for d in portdicts ]
    return Portfolio(portfolio)

Once you've made the change, trying reading a file with some errors:

>>> import report
>>> port = report.read_portfolio('Data/missing.csv')
Row 4: Couldn't convert ['MSFT', '', '51.23']
Row 4: Reason invalid literal for int() with base 10: ''
Row 7: Couldn't convert ['IBM', '', '70.44']
Row 7: Reason invalid literal for int() with base 10: ''
>>>

Now, try silencing the errors:

>>> import report
>>> port = report.read_portfolio('Data/missing.csv', silence_errors=True)
>>>

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关联来源

• summaries/01_Variable_arguments