in pandas how can I groupby weekday() for a datetime column?

Question

I\'d like to filter out weekend data and only look at data for weekdays (mon(0)-fri(4)). I\'m new to pandas, what\'s the best way to accomplish this in pandas?

Answer 1

your call to the function "weekday" does not work as it operates on the index of data.my_dt, which is an int64 array (this is where the error message comes from)

you could create a new column in data containing the weekdays using something like:

data['weekday'] = data['my_dt'].apply(lambda x: x.weekday())

then you can filter for weekdays with:

weekdays_only = data[data['weekday'] < 5 ]

I hope this helps

Answer 2

Faster way would be to use DatetimeIndex.weekday, like so:

temp = pd.DatetimeIndex(data['my_dt'])
data['weekday'] = temp.weekday

Much much faster, especially for a large number of rows. For further info, check this answer.