How could I get an am/pm date format?-CodePudding

I have this code:

arr=pd.date_range(start='1/1/2021', end='12/31/2021 23:00:00', freq='h')


df = pd.DataFrame({'year': arr.year})
dg = pd.DataFrame({'month': arr.month})
dh = pd.DataFrame({'day': arr.day})
di = pd.DataFrame({'hour': arr.hour,'minute': arr.minute,'second': arr.second})

I would like to get a csv format with an hourly frequency like this: "day,month,year,hour am" or "day,month,year,hour pm"

CodePudding user response：

I think this may be what you are looking for

timevalue_12hour = time.strftime( "%I:%M %p", t )

this would convert a time from datetime 24 hours format to 12 hours, the %I would convert the hour from 23 to 11 and the %p would get you the AM/PM value.

CodePudding user response：

Construct a new DataFrame with columns as maps over the date range with different format masks:

df = pd.DataFrame({
    "year": arr.map(lambda x: x.strftime("%Y")),
    "month": arr.map(lambda x: x.strftime("%m")),
    "day": arr.map(lambda x: x.strftime("%d")),
    "hour pm": arr.map(lambda x: x.strftime("%H:%M:%S %p")),
})

Than save it to .csv

df.to_csv("path/to/file.csv", sep=",", index=False)

CodePudding user response：

For any time format that you want you can use .strftime and then define the format you need. Check out this cheat sheet for possible options: https://strftime.org/

%I: Hour (12-hour clock) as a zero-padded decimal number.
%p: Locale’s equivalent of either AM or PM.

To get the format you want, this will do it:

arr.strftime('%d,%m,%Y,%I %p')

Output:

Index(['01,01,2021,12 AM', '01,01,2021,01 AM', '01,01,2021,02 AM',
       '01,01,2021,03 AM', '01,01,2021,04 AM', '01,01,2021,05 AM',
       '01,01,2021,06 AM', '01,01,2021,07 AM', '01,01,2021,08 AM',
       '01,01,2021,09 AM',
       ...
       '31,12,2021,02 PM', '31,12,2021,03 PM', '31,12,2021,04 PM',
       '31,12,2021,05 PM', '31,12,2021,06 PM', '31,12,2021,07 PM',
       '31,12,2021,08 PM', '31,12,2021,09 PM', '31,12,2021,10 PM',
       '31,12,2021,11 PM'],
      dtype='object', length=8760)

If you want to make that into a dataframe you can simply split it on the comma "," then convert to frame like this:

df = arr.strftime('%d,%m,%Y,%I %p').str.split(',', expand=True).to_frame(index=False)
df.columns = ['Day', 'Month', 'Year', 'Time']

Result:

    Day Month   Year    Time
0   01  01  2021    12 AM
1   01  01  2021    01 AM
2   01  01  2021    02 AM
3   01  01  2021    03 AM
4   01  01  2021    04 AM
... ... ... ... ...
8755    31  12  2021    07 PM
8756    31  12  2021    08 PM
8757    31  12  2021    09 PM
8758    31  12  2021    10 PM
8759    31  12  2021    11 PM
8760 rows × 4 columns