Python Pandas - Return the midpoint of the Interval

To return the midpoint of an Interval in Pandas, use the interval.mid property. The midpoint is calculated as the arithmetic mean of the left and right bounds: (left + right) / 2.

Creating an Interval

First, import Pandas and create an interval ?

import pandas as pd

# Create an open interval (excludes endpoints)
interval = pd.Interval(5, 20, closed='neither')
print("Interval:", interval)

Interval: (5, 20)

Finding the Midpoint

Use the mid property to get the midpoint ?

import pandas as pd

interval = pd.Interval(5, 20, closed='neither')
midpoint = interval.mid
print("Midpoint:", midpoint)

Midpoint: 12.5

Complete Example

Here's a comprehensive example showing interval properties including the midpoint ?

import pandas as pd

# Create an open interval
interval = pd.Interval(5, 20, closed='neither')

# Display interval properties
print("Interval:", interval)
print("Left bound:", interval.left)
print("Right bound:", interval.right)
print("Length:", interval.length)
print("Midpoint:", interval.mid)

Interval: (5, 20)
Left bound: 5
Right bound: 20
Length: 15
Midpoint: 12.5

Different Interval Types

The midpoint calculation works for all interval types ?

import pandas as pd

# Different interval types
open_interval = pd.Interval(0, 10, closed='neither')      # (0, 10)
closed_interval = pd.Interval(0, 10, closed='both')       # [0, 10]
left_closed = pd.Interval(0, 10, closed='left')           # [0, 10)
right_closed = pd.Interval(0, 10, closed='right')         # (0, 10]

intervals = [open_interval, closed_interval, left_closed, right_closed]
types = ['Open', 'Closed', 'Left-closed', 'Right-closed']

for interval, interval_type in zip(intervals, types):
    print(f"{interval_type}: {interval} ? Midpoint: {interval.mid}")

Open: (0, 10) ? Midpoint: 5.0
Closed: [0, 10] ? Midpoint: 5.0
Left-closed: [0, 10) ? Midpoint: 5.0
Right-closed: (0, 10] ? Midpoint: 5.0

Conclusion

The interval.mid property calculates the midpoint as (left + right) / 2, regardless of whether the interval is open, closed, or half-open. This provides a simple way to find the center point of any Pandas Interval.