如何根据匹配数据从csv中删除行

Question

我有大量的csv格式数据，需要根据匹配的两个参数从其中删除行。

我要删除的数据列表如下所示：

London,James Smith
London,John Oliver
London,John-Smith-Harrison
Paris,Hermione
Paris,Trevor Wilson
New York City,Charlie Chaplin
New York City,Ned Stark
New York City,Thoma' Becket
New York City,Ryan-Dover

然后，主csv将根据城市名称与第二列的匹配以及该名称与第9列的名称的匹配来删除行。

如果两者都匹配，请删除主csv中的行（请注意，此处未提供此csv的示例）。

Answer 1

我验证了以下内容是否可以根据您提供/描述的数据类型工作：

import csv
from cStringIO import StringIO

# parse the data you're about to filter with
with open('filters.csv', 'rb') as f:
    filters = {(row[0], row[1]) for row in csv.reader(f, delimiter=',')}

out_f = StringIO()  # use e.g. `with open('out.csv', 'wb') as out_f` for real file output
out = csv.writer(out_f, delimiter=',')

# go thru your rows and see if the pair (row[1], row[8]) is
# found in the previously parsed set of filters; if yes, skip the row
with open('data.csv', 'rb') as f:
    for row in csv.reader(f, delimiter=','):
        if (row[1], row[8]) not in filters:
            out.writerow(row)

# for debugging only
print out_f.getvalue()  # prints the resulting filtered CSV data

注：该{... for ... in ...}设置，理解语法; 根据您的Python版本，您可能需要将其更改为等效版本set(... for ... in ...)才能起作用。