Python 3.5通过匹配多个列来合并两个CSV

Question

I have two data sets. The first is like this:

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

The second file is like this:

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

What I want is as follows:

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

I have the following code, from forums that I have manipulated for my use:

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)

My problems are as follows: 1). I want to match between columns 0 and 1 (1 and 2);I am not matching between 2 columns; only one 2). The results do not include blank lines. For example, if nothing is found in the descriptors file that matches in data file, I would rather keep the data in the data file instead of throwing it away. The data file should be augmented by the descriptors file, not reduced.
3). I cannot figure out how to only write the descriptors column, not the entire 3 columns in the descriptors file

Answer 1

at first - your files are a bit incorrect:

1111111 != 11111111
77777777 != 777777777

I've fixed this and this code works well for me. Sorry for hardcode. if you need more complex solution - please tell what actually you want.

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:])