Question

我试图通过两列输出2个csv文件之间的差异，并创建第三个csv文件。如何通过第0列和第3列进行以下代码比较。

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Answer 1

如果你想要ted.csv中没有任何相同的第三和第四列元素的行作为ted2，从ted2创建一组这些元素并在写入之前检查ted.csv中的每一行：

with open("ted.csv") as f1, open("ted2.csv") as f2, open('foo.csv', 'w') as out:
    r1, r2 = csv.reader(f1), csv.reader(f2)
    st = set((row[0], row[3]) for row in r1)
    wr = csv.writer(out)
    for row in (row for row in r2 if (row[0],row[3]) not in st):
          wr.writerow(row)

如果你真的想要symmetric difference之类的东西，你可以从两个文件中获得唯一的行，那么从这两个文件中创建一组第三和第四列：

from itertools import chain

with open("ted.csv") as f1, open("ted2.csv") as f2, open('foo.csv', 'w') as out:
    r1, r2 = csv.reader(f1), csv.reader(f2)
    st1 = set((row[0], row[3]) for row in r1)
    st2 = set((row[0], row[3]) for row in r2)
    f1.seek(0), f2.seek(0)
    wr = csv.writer(out)
    r1, r2 = csv.reader(f1), csv.reader(f2)
    output1 = (row for row in r1 if (row[0], row[3]) not in st2)
    output2 = (row for row in r2 if (row[0], row[3]) not in st1)
    for row in chain.from_iterable((output1, output2)):
        wr.writerow(row)

使用Python操作csv文件

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