How do I check if a date in column is second Monday of the month and return True/False in Python?-CodePudding

first time here, so I have a data frame that is read from a csv file using Pathlib. It looks something like this

I want to create a new column, called 'Date Check' that verify each date on the date column and return 'True' if a pre-specified condition is met. In this case, return 'True' if the date is the second Monday of every month.

I have no experience with time or datetime library so please explain the code if you are using those.

Thanks !!!

Date	Date Check
2019/01/01
2019/01/02
2019/01/03
2019/01/04
...
2021/01/01
2021/01/02
2021/01/03

CodePudding user response：

you can make use of dt.day and dt.weekday attributes to select Monday and make sure it's the second of the month:

import pandas as pd

df = pd.DataFrame({'Date': pd.date_range('2020-01-01', '2020-01-31', freq='d')})

df['is_second_Monday'] = ((df['Date'].dt.weekday == 0) & # select Monday
                          (df['Date'].dt.day > 7) & # exclude first
                          (df['Date'].dt.day <= 14)) # exclude third etc.

print(df['Date'][df['is_second_Monday']])
# 12   2020-01-13
# Name: Date, dtype: datetime64[ns]