How do I get the day of week given a date?

Question

I want to find out the following: given a date (datetime object), what is the corresponding day of the week?

For instance, Sunday is the first day, Mond

Answer 1

We can take help of Pandas:

import pandas as pd

As mentioned above in the problem We have:

datetime(2017, 10, 20)

If execute this line in the jupyter notebook we have an output like this:

datetime.datetime(2017, 10, 20, 0, 0)

Using weekday() and weekday_name:

If you want weekdays in integer number format then use:

pd.to_datetime(datetime(2017, 10, 20)).weekday()

The output will be:

4

And if you want it as name of the day like Sunday, Monday, Friday, etc you can use:

pd.to_datetime(datetime(2017, 10, 20)).weekday_name

The output will be:

'Friday'

If having a dates column in Pandas dataframe then:

Now suppose if you have a pandas dataframe having a date column like this: pdExampleDataFrame['Dates'].head(5)

0   2010-04-01
1   2010-04-02
2   2010-04-03
3   2010-04-04
4   2010-04-05
Name: Dates, dtype: datetime64[ns]

Now If we want to know the name of the weekday like Monday, Tuesday, ..etc we can use .weekday_name as follows:

pdExampleDataFrame.head(5)['Dates'].dt.weekday_name

the output will be:

0    Thursday
1      Friday
2    Saturday
3      Sunday
4      Monday
Name: Dates, dtype: object

And if we want the integer number of weekday from this Dates column then we can use:

pdExampleDataFrame.head(5)['Dates'].apply(lambda x: x.weekday())

The output will look like this:

0    3
1    4
2    5
3    6
4    0
Name: Dates, dtype: int64