Python 3.5 通过匹配多列合并两个CSV

Question

我有两个数据集。第一个是这样的：

data file:
Column 1, Column 2, Column 3, Column 4, Column 5, Column 6
1111111,  2222222,  3333333,  44444444, 55555555, 666666666
0000000,  77777777, 8888888,  99999999, 10101010, 121212121
3333333,  55555555, 9999999,  88888888, 22222222, 111111111

第二个文件是这样的：

descriptors file:
Column 1, Column 2, Column 3
11111111,,           this is a descriptor
          ,777777777, this is a descriptor again
99999999, ,           last descriptor

我想要的是：

Column 1, Column 2, Column 3, Column 4, Column 5, Column 6, Column 7
1111111,  2222222,  3333333,  44444444, 55555555, 666666666, this is a descriptor
0000000,  77777777, 8888888,  99999999, 10101010, 121212121, this is a descriptor again
3333333,  55555555, 9999999,  88888888, 22222222, 111111111

我有以下代码，来自我操纵的论坛：

import csv

with open('descriptors file.CSV', 'r') as first_file:
  reader = csv.reader(first_file)
  first_header = next(reader, None)
  file_information = {row[0]: row for row in reader}

with open('data file.CSV', 'r') as second_file:
  with open('final results.csv', 'w', newline='') as outfile:
  reader = csv.reader(second_file)
  second_header = next(reader, None) 

  writer = csv.writer(outfile)
  writer.writerow(second_header[:6] + first_header[2:])

  for row in reader:
    if row[0] not in file_information: 
      continue


  newrow = row[0:] + file_information[row[0]]

  writer.writerow(newrow)

我的问题如下： 1).我想在第 0 列和第 1 列（1 和 2）之间进行匹配；我不在 2 列之间进行匹配；只有一个 2).结果不包括空行。例如，如果在描述符文件中找不到与数据文件匹配的任何内容，我宁愿将数据保留在数据文件中而不是将其丢弃。数据文件应该由描述符文件增加，而不是减少。
3).我不知道如何只写描述符列，而不是描述符文件中的整个 3 列

Answer 1

起初 - 您的文件有点不正确：

1111111 != 11111111
77777777 != 777777777

我已经解决了这个问题，这段代码对我来说效果很好。抱歉硬编码。如果您需要更复杂的解决方案 - 请说明您的实际需求。

import csv

with open('d_file.csv', 'r') as first_file:
    reader = csv.reader(first_file)
    first_header = next(reader, None)
    column0=  {}
    column1 = {}
    for row in reader:
        if row[0]:
            column0[row[0].strip()] = row[2]
        if row[1]:
            column1[row[1].strip()] = row[2]

with open('data_file.csv', 'r') as second_file:
    with open('final_results.csv', 'w', newline='') as outfile:
        reader = csv.reader(second_file)
        second_header = next(reader, None) 
        description = len(second_header)-1
        writer = csv.writer(outfile)
        # use there first_header[2:] is incorrect - you will save 'Column 3', while you want 'Column 7'
        writer.writerow(second_header[:6] + ['Column 7'])

        for row in reader:
            if row[0].strip() in column0:
                writer.writerow(row[0:] + [column0[row[0].strip()]] )
            elif row[1].strip() in column1:
                writer.writerow(row[0:] + [column1[row[1].strip()]] )
            else:
                writer.writerow(row[0:])

Python 3.5 通过匹配多列合并两个CSV

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