如何修复：TypeError：normalize（）参数2必须为str，而不是列表

Question

I'm making an api call that pulls the desired endpoints from ...url/articles.json and transforms it into a csv file. My problem here is that the ['labels_name'] endpoint is a string with multiple values.(an article might have multiple labels) How can I pull multiple values of a string without getting this error . "File "articles_labels.py", line 40, in <module> decode_3 = unicodedata.normalize('NFKD', article_label) TypeError: normalize() argument 2 must be str, not list" ?

import requests
import csv
import unicodedata
import getpass

url = 'https://......./articles.json'
user = ' '
pwd = ' '
csvfile = 'articles_labels.csv'

output_1 = []
output_1.append("id")
output_2 = []
output_2.append("title")
output_3 = []
output_3.append("label_names")
output_4 = []
output_4.append("link")

while url:
    response = requests.get(url, auth=(user, pwd))
    data = response.json()
    for article in data['articles']:
        article_id = article['id']
        decode_1 = int(article_id)
        output_1.append(decode_1)

    for article in data['articles']:
        title = article['title']
        decode_2 = unicodedata.normalize('NFKD', title)
        output_2.append(decode_2)

    for article in data['articles']:
        article_label = article['label_names']
        decode_3 = unicodedata.normalize('NFKD', article_label)
        output_3.append(decode_3) 

    for article in data['articles']:
        article_url = article['html_url']
        decode_3 = unicodedata.normalize('NFKD', article_url)
        output_3.append(decode_3)

    print(data['next_page'])
    url = data['next_page']

print("Number of articles:")
print(len(output_1))   

with open(csvfile, 'w') as fp:
    writer = csv.writer(fp,dialect = 'excel')
    writer.writerows([output_1])
    writer.writerows([output_2])
    writer.writerows([output_3])
    writer.writerows([output_4])

Answer 1

My problem here is that the ['labels_name'] endpoint is a string with multiple values.(an article might have multiple labels) How can I pull multiple values of a string

It's a list not a string, so you don't have "a string with multiple values" you have a list of multiple strings, already, as-is.

The question is what you want to do with them, CSV certainly isn't going to handle that, so you must decide on a way to serialise a list of strings to a single string eg by joining them together (with some separator like space or comma) or by just picking the first one (beware to handle the case where there is none), … either way the issue is not really technical.

Answer 2

unicodedata.normalize takes a unicode string, and not a list as the error says. The correct way to use unicodedata.normalize will be (example taken from How does unicodedata.normalize(form, unistr) work?

from unicodedata import normalize

print(normalize('NFD', u'\u00C7'))
print(normalize('NFC', u'C\u0327'))
#Ç
#Ç

Hence you need to make sure that unicodedata.normalize('NFKD', title) has title as a unicode string