Question

将此example用于CSV dictreader，如何将特定列和/或不同的顺序输出到CSV？

import csv
headers = ['Symbol', 'Price', 'Date', 'Time', 'Change', 'Volume']
rows = [{'Symbol':'AA', 'Price':39.48, 'Date':'6/11/2007',
          'Time':'9:36am', 'Change':-0.18, 'Volume':181800},
        {'Symbol':'AIG', 'Price': 71.38, 'Date':'6/11/2007',
          'Time':'9:36am', 'Change':-0.15, 'Volume': 195500},
        {'Symbol':'AXP', 'Price': 62.58, 'Date':'6/11/2007',
          'Time':'9:36am', 'Change':-0.46, 'Volume': 935000},
        ]

with open('stocks.csv','w') as f:
    f_csv = csv.DictWriter(f, headers)
    f_csv.writeheader()
    f_csv.writerows(rows)

我如何输出音量，然后输出日期（列重新排序，2列未输出）？

Answer 1

将extrasaction参数用于np.maximum：

with open('stocks.csv','w') as f:
    f_csv = csv.DictWriter(f, ['Volume','Date'], extrasaction='ignore')
    f_csv.writeheader()
    f_csv.writerows(rows)

结果：

Volume,Date
181800,6/11/2007
195500,6/11/2007
935000,6/11/2007

Answer 2

我对dictwriter并不是很熟悉，但你可以用你想要的字段建立一个字典列表

myfields = ['Volume', 'Date']
myrows = []
for row in rows:
    myrow = {}
    for field in myfields:
        myrow[field] = row.get(field)
    myrows.append(myrow)
f_csv = csv.DictWriter(f, myfields)
f_csv.writeheader()
f_csv.writerows(myrows)

从词典，如何将特定列输出到CSV

2 个答案: