You can use the following syntax to convert an index column of a pandas DataFrame to a datetime format:
df.index = pd.to_datetime(df.index)
The following example shows how to use this syntax in practice.
Example: Convert Index Column to Datetime in Pandas
Suppose we have the following pandas DataFrame that contains information about product sales at some store:
import pandas as pd #create DataFrame df = pd.DataFrame({'time': ['4-15-2022 10:15', '5-19-2022 7:14', '8-01-2022 1:14', '6-14-2022 9:45', '10-24-2022 2:58', '12-13-2022 11:03'], 'product': ['A', 'B', 'C', 'D', 'E', 'F'], 'sales': [12, 25, 23, 18, 14, 10]}) #set 'time' column as index df = df.set_index('time') #view DataFrame print(df) product sales time 4-15-2022 10:15 A 12 5-19-2022 7:14 B 25 8-01-2022 1:14 C 23 6-14-2022 9:45 D 18 10-24-2022 2:58 E 14 12-13-2022 11:03 F 10
Now suppose we attempt to create a new column that contains the hour of the time in the index column:
#attempt to create new column that contains hour of index column
df['hour'] = df.index.hour
AttributeError: 'Index' object has no attribute 'hour'
We receive an error because the index column is not currently in a datetime format so it doesn’t contain an ‘hour’ attribute.
To avoid this error, we can use the pandas to_datetime() function to convert the index column to a datetime format:
#convert index column to datetime format
df.index = pd.to_datetime(df.index)
#create new column that contains hour of index column
df['hour'] = df.index.hour
#view updated DataFrame
print(df)
product sales hour
time
2022-04-15 10:15:00 A 12 10
2022-05-19 07:14:00 B 25 7
2022-08-01 01:14:00 C 23 1
2022-06-14 09:45:00 D 18 9
2022-10-24 02:58:00 E 14 2
2022-12-13 11:03:00 F 10 11
By using the to_datetime() function, we’re able to convert the index column to a datetime format.
Thus, we’re able to successfully create a new column called hour that contains the hour of the time in the index column without receiving any error.
Note: You can find the complete documentation for the pandas to_datetime() function here.
Additional Resources
The following tutorials explain how to perform other common operations in pandas:
How to Create a Date Range in Pandas
How to Convert Timestamp to Datetime in Pandas
How to Calculate a Difference Between Two Dates in Pandas