Python如何替换csv中列中的值

Question

我想在某些情况下更改和替换一些值。

我的csv看起来像:

   Date
0  2022-11-05
1  2022-11-06
2  2022-11-08
3  2022-11-09

如果是星期六，我想要日期+2，如果是星期日，我想要日期+1，并替换原始csv中的值。

df = pd.read_csv('Book1.csv')
date = df["Date"]
for d in date:
    date_object = datetime.strptime(d, '%Y-%m-%d').date()
    #print(date_object)
    weekdayidx=date_object.isoweekday()
    #print(weekdayidx)
    if weekdayidx == 6:
       date_final = date_object.replace(day=date_object.day + 2)
    elif weekdayidx == 7:
       date_final = date_object.replace(day=date_object.day + 1)
    else:
        date_final = date_object
    print(date_final)
df['Date'] = df['Date'].replace({'d': 'date_final'})
df.to_csv("Book1.csv", index=False)
print(df)

但是结果还是和原来的csv一样，没有更新，不确定原因

输出:

0  2022-11-05
1  2022-11-06
2  2022-11-08
3  2022-11-09

但是我想:

2022-11-07
2022-11-07
2022-11-08
2022-11-09

谢谢!

Answer 1

我做了一些轻微的改变，这似乎工作。随着我所做的更改，我只是将数据帧更新为多维数组。

df = pd.read_csv('Book1.csv')
date = df["Date"]
for i in range(0, len(date)):
    d = date[i]
    date_object = datetime.strptime(d, '%Y-%m-%d').date()
    #print(date_object)
    weekdayidx=date_object.isoweekday()
    #print(weekdayidx)
    if weekdayidx == 6:
       date_final = date_object.replace(day=date_object.day + 2)
    elif weekdayidx == 7:
       date_final = date_object.replace(day=date_object.day + 1)
    else:
        date_final = date_object
    print(date_final)
    date[i] = date_final
df.to_csv("Book1.csv", index=False)
print(df)

Answer 2

按如下方式遍历每一行:

import pandas as pd
from datetime import datetime
df = pd.read_csv('Book1.csv')
for i in range(len(df)):
    d = df.iloc[i].Date
    date_object = datetime.strptime(d, '%Y-%m-%d').date()
    #print(date_object)
    weekdayidx=date_object.isoweekday()
    #print(weekdayidx)
    if weekdayidx == 6:
       date_final = date_object.replace(day=date_object.day + 2)
    elif weekdayidx == 7:
       date_final = date_object.replace(day=date_object.day + 1)
    else:
        date_final = date_object
    print(date_final)
    df.iloc[i].Date = date_final
    
df.to_csv("Book1.csv", index=False)
print(df)