python - 使用 DictReader 从 csv 读取特定列

Question

我从 csv 文件中获取第二列值时遇到问题。

以下代码将数据写入 csv 文件

def save_tweet_to_csv(ticker, tweet, emotion, confidence):
    file = Path(url_path + ticker + '_tweets.csv')
    if file.is_file():
        mode = 'a'
    else: 
        mode = 'w'
    with open(url_path + ticker + '_tweets.csv', mode, newline="\n", encoding="utf-8") as csvfile:
        fieldnames = ['tweet', 'emotion', 'confidence']
        writer = csv.DictWriter(csvfile, fieldnames=fieldnames)
        if mode == 'w':
            writer.writeheader()
        writer.writerow({'tweet': tweet, 'emotion': emotion, 'confidence': confidence})

我正在尝试通过以下方式从 csv中获取情感列

def plot_tweets_csv(ticker):
    file = Path(url_path + ticker + '_tweets.csv')
    emotions = []
    with open(file, 'r', encoding="utf8") as csvfile:
        reader = csv.DictReader(file)
        for row in reader :
            print(row['emotion'])

但我不断得到那个

文件 ....\Python36\lib\csv.py"，第 87 行，在init self.reader = reader(f, dialect, *args, **kwds) TypeError: argument 1 must be an iterator

知道这里可能出了什么问题吗？

标签： pythoncsv

Answer 1

我认为您需要从更改file为csvfile

with open(file, 'r', encoding="utf8") as csvfile:
    reader = csv.DictReader(csvfile)
    ...