如果使用python获得最后一列的值，那么如何获得csv文件中第一列或第二列的值

Question

我正在建立汽车生日愿望项目。到目前为止，我已经设法循环了一个月

with open("birthdays.csv") as birthday_file:
    birthday = pd.read_csv(birthday_file)
    month_data = birthday.month
    date_data = birthday.day
    birthday_month = [month for month in month_data]
    birthday_date = [day for day in date_data]

csv文件包含以下信息

name, email, year, month, day
Test, [e-mail],1961,12,21
Charlotte, [e-mail], 2021,08,22

Answer 1

例如，请尝试以下操作：

import pandas as pd

# open the file to a dataframe called 'df'
# df = pd.read_csv('yourFile.csv')

# for this demo use:
df = pd.DataFrame({'name': {0: 'Test', 1: 'Charlotte'},
 ' email': {0: '[e-mail]', 1: '[e-mail]'},
 ' year': {0: 1961, 1: 2020},
 ' month': {0: 12, 1: 8},
 ' day': {0: 21, 1: 25}})

# remove spaces in the column names
df.columns = df.columns.str.replace(' ', '')

# get the individual columns that make up the date to a column with a datetime format
df = df.astype({'year': 'str', 'month': 'str', 'day': 'str'})
df['date'] = df[['year', 'month', 'day']].agg('-'.join, axis=1)
df['date'] = pd.to_datetime(df['date'], format='%Y-%m-%d')
del df['month'], df['year']

print(df)

'''
    >>         name           email day         date
    >> 0       Test  [e-mail]  21   1961-12-21
    >> 1  Charlotte    [e-mail]  25   2020-08-25
'''

# create a function to return all email addresses (as a list)
# where the month matches the current month and the day is one week in the future
def sendReminders(delay=7):
    
    return (df.loc[(df['date'].dt.dayofyear > pd.Timestamp.now().dayofyear) &
                    (df['date'].dt.dayofyear <= (pd.Timestamp.now().dayofyear + delay)), 'email'].tolist())
    
# call the function to return a list of emails for reminders but override the 7 days and set to 5 day as an example
print(sendReminders(5))

'''
    >> ['[e-mail]']
'''

print('\n')

显然，您需要继续添加更多函数等。关键是要清理数据，并以正确的格式获得正确的列。一旦将数据帧中的数据组织起来，就可以进行各种计算。很可能已经有了一种方法，你只需要找到它。