You can extract the year from the DateTime (date) column in pandas in several ways. In this article, I will explain how to get a year from the Datetime column using pandas.Series.dt.year, pandas.DatetimeIndex properties and strftime() functions.
If the data is not in Datetime type, you need to convert it first to Datetime by using the pd.to_datetime() method.
1. Quick Examples of Extract Year from Datetime
If you are in a hurry, below are some quick examples of how to extract the year from the pandas DataFrame DateTime column.
# Below are the quick examples of get the year from the datetime column
# Example 1: Use Datetime.strftime() Method to extract year
df['Year'] = df['InsertedDate'].dt.strftime('%Y')
# Example 2: Using pandas.Series.dt.year()
df['Year'] = df['InsertedDate'].dt.year
# Example 3: Using pandas.DatetimeIndex() to extract year
df['year'] = pd.DatetimeIndex(df['InsertedDate']).year
# Example 4: Use datetime.to_period() method to extract year
df['Month_Year'] = df['InsertedDate'].dt.to_period('y')
# Example 5: Use DataFrame.apply() with lambda function and strftime()
df['Year'] = df['InsertedDate'].apply(lambda x: x.strftime('%Y'))
# Example 6: Use Pandas.to_datetime() and datetime.strftime() method
df['yyyy'] = pd.to_datetime(df['InsertedDate']).dt.strftime('%Y')
2. Pandas Extract Year using Datetime.strftime()
Let’s create a Pandas DataFrame with the column of Datetime in the form of year, month, and day and use Pandas attributes and functions to extract the year from a given datetime column.
import pandas as pd
import numpy as np
import datetime
Dates = ["2018-08-14","2019-10-17","2020-11-14","2020-05-17","2021-09-15","2021-12-14"]
Courses =["Spark","PySpark","Hadoop","Python","Pandas","Hadoop"]
df = pd.DataFrame({'InsertedDate': pd.to_datetime(Dates)},index=Courses)
print("Create DataFrame:\n", df)
Yields below output. This example extracts the year and add as a new column to DataFrame.
Yields below output.
strftime() method takes the datetime format and returns a string representing the specific format. You can use %Y as format code to extract the year from the DataFrame. Here, pd.to_datetime() is used to convert String to Datetime.
# Use Datetime.strftime() Method to extract year
df['Year'] = df['InsertedDate'].dt.strftime('%Y')
print("Get the year from the datetime column:\n", df)
Yields below output.
3. Extract Year Using Series.dt.year()
We can use pandas.Series.dt.year() to extract year but, this function returns a series object. Assign these to a column to get a DataFrame with year columns.
# Using pandas.Series.dt.year()
df['Year'] = df['InsertedDate'].dt.year
print("Get the year from the datetime column:\n", df)
Yields below output.
# Output:
# Get the year from the datetime column:
InsertedDate Year
Spark 2018-08-14 2018
PySpark 2019-10-17 2019
Hadoop 2020-11-14 2020
Python 2020-05-17 2020
Pandas 2021-09-15 2021
Hadoop 2021-12-14 2021
4. Use Pandas DatetimeIndex() to Extract Year
We can also extract the year from the Pandas Datetime column, using the DatetimeIndex.year attribute. Note that this method takes a date as an argument.
# Using pandas.DatetimeIndex() to extract year
df['year'] = pd.DatetimeIndex(df['InsertedDate']).year
print("Get the year from the datetime column:\n", df)
Yields the same output as above.
5. Use Datetime.to_period() Method to Extract Year
You can also use df['Year']=df['InsertedDate'].dt.to_period('Y') method. The df['date_column'] has to be in datetime format.
# Use datetime.to_period() method to year
df['Year'] = df['InsertedDate'].dt.to_period('Y')
print("Get the year from the datetime column:\n", df)
Yields below output.
# Output:
# Get the year from the datetime column:
InsertedDate Year
Spark 2018-08-14 2018
PySpark 2019-10-17 2019
Hadoop 2020-11-14 2020
Python 2020-05-17 2020
Pandas 2021-09-15 2021
Hadoop 2021-12-14 2021
6. Use DataFrame.apply() With Lambda Function and strftime()
Let’s see how to get the year by using Pandas DataFrame.apply() and lambda function.
# Use DataFrame.apply() with lambda function and strftime()
df['Year'] = df['InsertedDate'].apply(lambda x: x.strftime('%Y'))
print("Get the year from the datetime column:\n", df)
Yields below output.
# Output:
# Get the year from the datetime column:
InsertedDate Year
Spark 2018-08-14 2018
PySpark 2019-10-17 2019
Hadoop 2020-11-14 2020
Python 2020-05-17 2020
Pandas 2021-09-15 2021
Hadoop 2021-12-14 2021
7. Use Pandas.to_datetime() and datetime.strftime() Method
Use Pandas.to_datetime() and datetime.strftime() to get the year.
# Use Pandas.to_datetime() and datetime.strftime() method
df['yyyy'] = pd.to_datetime(df['InsertedDate']).dt.strftime('%Y')
print("Get the year from the datetime column:\n", df)
Yields below output.
# Output:
# Get the year from the datetime column:
InsertedDate yyyy
Spark 2018-08-14 2018
PySpark 2019-10-17 2019
Hadoop 2020-11-14 2020
Python 2020-05-17 2020
Pandas 2021-09-15 2021
Hadoop 2021-12-14 2021
Frequently Asked Questions on Pandas Extract Year from Datetime
You can use the dt attribute in Pandas to extract the year from a datetime column. For example, df['year'] = df['datetime_column'].dt.year
you can extract the year without creating a new column by simply accessing the dt.year attribute. For example, df['year'] = pd.to_datetime(df['datetime_column']).dt.year
If your DataFrame has a datetime index, you can use the year attribute directly on the index. For example, df.set_index('timestamp', inplace=True)df['year'] = df.index.year
8. Conclusion
In this article, you have learned how to extract the year from the Pandas DateTime column by using pandas.Series.dt.strftime(), pandas.DatetimeIndex(), datetime.to_period() and DataFrame.apply() methods with examples.
Happy Learning !!
Related Articles
- Get Pandas DataFrame Columns by Data Type
- Pandas Filter DataFrame by Multiple Conditions
- Select Pandas DataFrame Rows Between Two Dates
- How to Format Pandas Datetime?
- Pandas DatetimeIndex Usage Explained
- Convert Pandas DatetimeIndex to String
- pandas Convert Datetime to Seconds
- Sort Pandas DataFrame by Date (Datetime)
- Pandas Get Day, Month and Year from DateTime
- Pandas Extract Month and Year from Datetime
- Pandas Convert Integer to Datetime Type
- Pandas Convert Datetime to Date Column
- Pandas Convert Date (datetime) to String Format
- Pandas Convert Multiple Columns To DateTime Type
- Pandas Convert Column To DateTime
