Python get month from date (simply explained)

Being able to get the month number, or year month number, from a DateTime object in Python can be extremely helpful for feature engineering. In this post, I will walk through how to do this simply in multiple variations.

How do you get the month number from a datetime object in Python?

In order to get the month number from a datetime object in Python, all you need to do is use the .month method. This is a much simpler operation than getting, for example, the week number as there aren’t multiple interpretations of the aggregation.

python code for getting month number from datetime object

Python get month from date

Getting the month number from a datetime object in Python requires very little code, here is the most simple example of implementing it.

import datetime

date = datetime.date(2022, 9, 1)

month_number = date.month

print(date)
print(f"Month number is: {month_number}")

"""
Output:

2022-09-01
Month number is: 9
"""

Pandas get month number from datetime

If you’re using Pandas as a way to store your data then you can easily get the month number from a datetime column by using the .dt.month method.

import pandas as pd

df = pd.DataFrame(
	columns=["datetime"],
	data=pd.date_range("30/8/2022 09:00:00", periods=4, freq="D"))

df["month_number"] = df["datetime"].dt.month

"""
Output:

datetime                 month_number
0 2022-08-30 09:00:00    8
1 2022-08-31 09:00:00    8
2 2022-09-01 09:00:00    9
3 2022-09-02 09:00:00    9
"""

Python get year month number from date

If you have a dataset that spans multiple years then you may want to return a combination of year and month to make it unique. Here is how this can be done in Python using strftime

import datetime

date = datetime.date(2022, 9, 1)

year_month = date.strftime('%Y-%m')

print(date)
print(f"Year month combination: {year_month}")

"""
Output:

2022-09-01
Year month combination: 2022-09
"""

Pandas get year month number from datetime

It’s also possible to calculate this unique year-month combination for a Pandas dataframe using the same approach.

import pandas as pd

df = pd.DataFrame(
	columns=["datetime"],
	data=pd.date_range("30/8/2022 09:00:00", periods=4, freq="D"))

df["year_month"] = df["datetime"].dt.strftime('%Y-%m')

"""
Output:

datetime                 year_month
0 2022-08-30 09:00:00    2022-08
1 2022-08-31 09:00:00    2022-08
2 2022-09-01 09:00:00    2022-09
3 2022-09-02 09:00:00    2022-09
"""

Python round DateTime to day
Python round DateTime to week
Python round DateTime to start or end of month
Python get week number from DateTime
Python convert datetime64 to date
Python get year from DateTime

References

Python datetime documentation
Pandas datetime documentation

Stephen Allwright

Stephen Allwright

I'm a Data Scientist currently working for Oda, an online grocery retailer, in Oslo, Norway. These posts are my way of sharing some of the tips and tricks I've picked up along the way.
Oslo, Norway