Python: take unique dates in dataframe-CodePudding

I have a data frame that looks like this:

                       price
Date
2022-01-01 19:20:00    100   
2022-01-01 19:27:00    100
2022-01-02 19:31:00    102

I want the dataframe to only have unique dates:

                       price
Date
2022-01-01 19:20:00    100   
2022-01-02 19:31:00    102

How can I achieve that?

CodePudding user response：

You can sort the dataframe with:

df = df.sort_values('Date')

And than leave only the rows with a new date with:

df = df[df['Date'].dt.date != df['Date'].shift().dt.date]

CodePudding user response：

You can extract the date from the datetime column using df.Date.dt.date, put that into a new column using assign, and after that use drop_duplicates based on only that column. Last, you might want to drop the newly create column that has only the date information. In code that reads

df = (
    df.assign(new_date=lambda df:df.Date.dt.date)
   .drop_duplicates(subset=["new_date"])
   .drop(columns=["new_date"])
)