Python比较两个列表

Question

I'm trying to find all the rows inside training_full.csv (two column,"macroclass" and "description") from contatti.csv (containing two columns, "name" and "surname"). I want to retrieve all the rows of "description", inside training_full.csv, in which there is "name" and "surname" contained in contatti.csv.

The script I've created seems to evaluate only the first row of training_full.csv and, for this reason, print only the first row of training_full.csv (in which the script finds a match). If I modify training_full.csv in way that in the first row there isn't any match, the result is empty.

Here the code:

import csv

match=[]

with open('xxxxxxxxxxx/training_full1.csv', encoding='utf-8') as csvfile, open('output.csv', 'wb') as output, open('xxxxxxxxxxx/contatti.CSV') as contatti:
spamreader = csv.reader(csvfile)
spamreader_contacts = csv.reader(contatti, delimiter=';')
spamwriter = csv.writer(output)
for row_desc in spamreader:
    #print(righe[0])
    for row_cont in spamreader_contacts:
        #print(row[0])
        if (row_cont[0] + " " + row_cont[1]) in row_desc[0]:
            match.append(row_desc[0])

print(match)

Thanks for any help,

Filippo.

Answer 1

Looking at your problem, it seems to be separable in three parts: 1) Read the names, and build a list 2) Compare the training file with the names list 3) Write the matches

Doing that, we can end up with a solution similar to:

import csv

names = []
with open('xxxxxxxxxxx/contatti.csv', 'rb') as f:
    contatti = csv.reader(f, delimiter=';')
    for row in contatti:
        names.append("{} {}".format(row[0], row[1]))

matches=[]
with open('xxxxxxxxxxx/training_full1.csv', 'rb', encoding='utf-8') as f:
    training = csv.reader(f)
    for row in training:
        for name in names:
            if name in row[1]: # description being the second column 
                matches.append(row[1])
                break

with open('output.csv', 'wb') as f:
    output = csv.writer(f)
    for match in matches:
        output.writerow(match)

print(matches)

The main issue with your solution attempt, was, as pointed out in the comments, that once you looked for the first match, you exhausted your csv reader. In the solution I present, a list of names is first being built. This will ensure that we can search the for names multiple times.