Python Pandas - Get the day of the week from the PeriodIndex object

To get the day of the week from the PeriodIndex object, use the PeriodIndex.weekday property. This property returns the day of the week as integers, where Monday=0, Tuesday=1, Wednesday=2, Thursday=3, Friday=4, Saturday=5, and Sunday=6.

Creating a PeriodIndex Object

First, let's create a PeriodIndex object with datetime strings and specify the frequency ?

import pandas as pd

# Create a PeriodIndex object with minute frequency
periodIndex = pd.PeriodIndex(['2021-09-25 07:30:35', '2019-10-30 04:15:45',
                             '2021-07-15 02:55:15', '2022-06-25 09:40:55'], freq="T")

print("PeriodIndex...")
print(periodIndex)

PeriodIndex...
PeriodIndex(['2021-09-25 07:30', '2019-10-30 04:15', '2021-07-15 02:55', '2022-06-25 09:40'], dtype='period[T]')

Getting the Day of Week

Use the weekday property to extract the day of the week from each period ?

import pandas as pd

periodIndex = pd.PeriodIndex(['2021-09-25 07:30:35', '2019-10-30 04:15:45',
                             '2021-07-15 02:55:15', '2022-06-25 09:40:55'], freq="T")

# Get day of week (Monday=0, Sunday=6)
weekdays = periodIndex.weekday
print("Day of week from PeriodIndex:")
print(weekdays)

# Display with actual day names for clarity
day_names = ['Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday', 'Sunday']
print("\nCorresponding day names:")
for i, day_num in enumerate(weekdays):
    print(f"{periodIndex[i].strftime('%Y-%m-%d')}: {day_names[day_num]}")

Day of week from PeriodIndex:
Index([5, 2, 3, 5], dtype='int64')

Corresponding day names:
2021-09-25: Saturday
2019-10-30: Wednesday  
2021-07-15: Thursday
2022-06-25: Saturday

Complete Example

Here's a comprehensive example showing PeriodIndex properties including weekday ?

import pandas as pd

# Create a PeriodIndex object
periodIndex = pd.PeriodIndex(['2021-09-25 07:30:35', '2019-10-30 04:15:45',
                             '2021-07-15 02:55:15', '2022-06-25 09:40:55'], freq="T")

print("PeriodIndex:")
print(periodIndex)

print("\nFrequency object:")
print(periodIndex.freq)

print("\nFrequency as string:")
print(periodIndex.freqstr)

print("\nWeek numbers:")
print(periodIndex.week)

print("\nDay of week (0=Monday, 6=Sunday):")
print(periodIndex.weekday)

PeriodIndex:
PeriodIndex(['2021-09-25 07:30', '2019-10-30 04:15', '2021-07-15 02:55', '2022-06-25 09:40'], dtype='period[T]')

Frequency object:
<Minute>

Frequency as string:
T

Week numbers:
Index([38, 44, 28, 25], dtype='int64')

Day of week (0=Monday, 6=Sunday):
Index([5, 2, 3, 5], dtype='int64')

Conclusion

The weekday property of PeriodIndex returns integer values representing days of the week, with Monday as 0 and Sunday as 6. This is useful for time-based analysis and filtering operations in pandas.