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+--- Thread: Filtering with IF Statement (/thread-22836.html)
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RE: Filtering with IF Statement - perfringo - Nov-29-2019
csv.DictReader will create dictionary for every row according to mapping. If table in csv file is in table format it's maps to first row, but as your file is 'headless' then you should provide headers separately.
What good it does? Instead of indices you can use dictionary keys. As far as I understand, only four datapoints per row is needed (other data is mapped to underscores):
>>> from csv import DictReader
>>> headers = ['Disease', '_', 'State', 'Instances', '__', 'Year']
>>> with open('health_no_head_sample.csv', 'r', encoding='UTF-8') as f:
... data = list(DictReader(f, fieldnames=headers))
...
>>> data[:2]
[OrderedDict([('Disease', 'MEASLES'),
('_', '206.98'),
('State', 'COLORADO'),
('Instances', '2099'),
('__', '1014000'),
('Year', '1928')]),
OrderedDict([('Disease', 'MEASLES'),
('_', '634.95'),
('State', 'CONNECTICUT'),
('Instances', '10014'),
('__', '1577000'),
('Year', '1928')])]
>>> [row for row in data if row['State'] == 'COLORADO']
[OrderedDict([('Disease', 'MEASLES'),
('_', '206.98'),
('State', 'COLORADO'),
('Instances', '2099'),
('__', '1014000'),
('Year', '1928')]),
OrderedDict([('Disease', 'POLIO'),
('_', '7.04'),
('State', 'COLORADO'),
('Instances', '71'),
('__', '1014000'),
('Year', '1928')]),
OrderedDict([('Disease', 'SMALLPOX'),
('_', '33.58'),
('State', 'COLORADO'),
('Instances', '340'),
('__', '1014000'),
('Year', '1928')]),
/..../
>>> [row['State'], row['Disease'], row['Instances'], row['Year'] for row in data if row['State'] == 'COLORADO' and row['Year'] == '1929']
[('COLORADO', 'MEASLES', '748', '1929'),
('COLORADO', 'POLIO', '13', '1929'),
('COLORADO', 'SMALLPOX', '844', '1929')]