获取第一列CSV Python文件

Question

尝试将第一列(名称)输入列表以显示用户，然后通过对CSV文件的更改进行更新。使用此代码：

import csv
list = []
exRtFile = open ('exchangeRate.csv','r')
exchReader = csv.reader(exRtFile)
while True:
    for column in exchReader:
        list.append(column and column[0])
        print(list)
        exRtFile.close

然而，我得到的结果是：

['US Dollar']
['US Dollar', []]
['US Dollar', [], 'Japanese Yen']
['US Dollar', [], 'Japanese Yen', []]
['US Dollar', [], 'Japanese Yen', [], 'Euro']
['US Dollar', [], 'Japanese Yen', [], 'Euro', []]
['US Dollar', [], 'Japanese Yen', [], 'Euro', [], 'Pound Sterling']
['US Dollar', [], 'Japanese Yen', [], 'Euro', [], 'Pound Sterling', []]
['US Dollar', [], 'Japanese Yen', [], 'Euro', [], 'Pound Sterling', [], 'Japanese Yen']

Answer 1

每隔一行追加一次空的column列表；在追加之前对列进行测试：

col = []
exRtFile = open ('exchangeRate.csv','r')
exchReader = csv.reader(exRtFile)
for column in exchReader:
    if column:
        col.append(column[0])

不要在那里使用无止境的循环(while True:)。

或者使用列表理解和文件作为上下文管理器自动关闭它：

with open('exchangeRate.csv', newline='') as exRtFile:
    exchReader = csv.reader(exRtFile)
    col = [c[0] for c in exchReader if c]

注意，我将newline=''参数添加到open()调用中；这是对CSV文件的推荐，因为它们可以在值和行之间使用行尾的组合，如果允许的话，csv.reader()将为您管理行尾。