Python Pandas - Return an Index of formatted strings specified by date format

The DateTimeIndex.strftime() method in Pandas returns an Index of formatted strings based on a specified date format. This method is useful for converting datetime objects into human-readable string representations.

Syntax

DateTimeIndex.strftime(date_format)

Parameters:

• date_format ? A string specifying the format using strftime directives

Creating a DateTimeIndex

First, let's create a DateTimeIndex with timezone information ?

import pandas as pd

# Create DatetimeIndex with period 7 and frequency as 2 days
datetimeindex = pd.date_range('2021-10-30 02:30:50', periods=7, tz='Australia/Adelaide', freq='2D')

print("DateTimeIndex...")
print(datetimeindex)

DateTimeIndex...
DatetimeIndex(['2021-10-30 02:30:50+10:30', '2021-11-01 02:30:50+10:30',
               '2021-11-03 02:30:50+10:30', '2021-11-05 02:30:50+10:30',
               '2021-11-07 02:30:50+10:30', '2021-11-09 02:30:50+10:30',
               '2021-11-11 02:30:50+10:30'],
              dtype='datetime64[ns, Australia/Adelaide]', freq='2D')

Using strftime() to Format Dates

Now let's format these dates using various strftime directives ?

import pandas as pd

# Create DatetimeIndex
datetimeindex = pd.date_range('2021-10-30 02:30:50', periods=7, tz='Australia/Adelaide', freq='2D')

# Format with different directives
formatted_dates = datetimeindex.strftime('%b. %d, %Y was a %A')
print("Formatted dates:")
print(formatted_dates)

Formatted dates:
Index(['Oct. 30, 2021 was a Saturday', 'Nov. 01, 2021 was a Monday',
       'Nov. 03, 2021 was a Wednesday', 'Nov. 05, 2021 was a Friday',
       'Nov. 07, 2021 was a Sunday', 'Nov. 09, 2021 was a Tuesday',
       'Nov. 11, 2021 was a Thursday'],
      dtype='object')

Common Format Directives

Here are different format patterns you can use with strftime() ?

import pandas as pd

datetimeindex = pd.date_range('2021-10-30', periods=3, freq='D')

print("ISO format:", datetimeindex.strftime('%Y-%m-%d'))
print("US format:", datetimeindex.strftime('%m/%d/%Y'))
print("Full format:", datetimeindex.strftime('%A, %B %d, %Y'))
print("Short format:", datetimeindex.strftime('%a, %b %d'))

ISO format: Index(['2021-10-30', '2021-10-31', '2021-11-01'], dtype='object')
US format: Index(['10/30/2021', '10/31/2021', '11/01/2021'], dtype='object')
Full format: Index(['Saturday, October 30, 2021', 'Sunday, October 31, 2021',
       'Monday, November 01, 2021'],
      dtype='object')
Short format: Index(['Sat, Oct 30', 'Sun, Oct 31', 'Mon, Nov 01'], dtype='object')

Key Format Codes

Conclusion

The strftime() method provides flexible date formatting for DateTimeIndex objects. Use format directives like %Y, %m, %d to create custom date string representations that suit your specific needs.