更新 Python 中的 CSV 文件

Question

I am trying to update a csv file, https://www.kaggle.com/carolzhangdc/imdb-5000-movie-dataset .

At the end of this csv file I am trying to append a new url to the image of the movie.

my code is below

import csv
from bs4 import BeautifulSoup
import urllib2

with open('movie_metadata.csv') as csv_file:
    csv_reader = csv.reader(csv_file, delimiter=',')
    line_count = 0
    for row in csv_reader:
        if line_count == 0:
            print('Column names are {}'.format(", ".join(row)))
            row[-1] = "movie_links"
            line_count += 1
        else:
            imdb_link = row[17]
            soup = BeautifulSoup(urllib2.urlopen(imdb_link).read(), features="html.parser")
            link = soup.find_all('div', {'class': 'poster'})
            if link:
                row[-1] = link[0].find('img')['src']
            line_count += 1
    print('Processed {} lines.'.format(line_count))

I am creating a new row at row[-1] and trying to update the csv file if link:

But it's not updating my csv file at all, it stays the same after I run my code.

Answer 1

Do you realize you overwrite the last element in the array row ? You should append() instead of changing [-1] . Try:

row.append("movie_links") instead of row[-1] = "movie_links"

and

row.append(link[0].find('img')['src']) instead of row[-1] = link[0].find('img')['src'] .

Then, to actually write the CSV file, use csv.writer with the new row (documentation here: https://docs.python.org/3/library/csv.html ).

Note, row + ["movie links"] for the first one is another way to append. Using [-1] Overwrites the last element instead of appending. Let me know if you want me to code you the csv writing portion.