Python Pandas IntervalIndex - Check if Intervals that only have an open endpoint in common overlap or not

To check if intervals that only have an open endpoint in common overlap or not, use the IntervalIndex.is_overlapping property. This property returns True if any intervals overlap, and False if they only share open endpoints.

Understanding Interval Overlapping

Intervals with open endpoints like [0, 1) and [1, 2) share the point 1, but since it's open in the first interval and closed in the second, they don't actually overlap ?

Creating IntervalIndex with Left-Closed Intervals

First, let's create an IntervalIndex with left-closed intervals ?

import pandas as pd

# Create IntervalIndex with left-closed intervals
interval = pd.interval_range(0, 8, closed='left')

# Display the interval
print("IntervalIndex...")
print(interval)

IntervalIndex...
IntervalIndex([[0, 1), [1, 2), [2, 3), [3, 4), [4, 5), [5, 6), [6, 7), [7, 8)], dtype='interval[int64, left]')

Checking for Overlapping Intervals

Now let's check if these intervals overlap using the is_overlapping property ?

import pandas as pd

# Create IntervalIndex with left-closed intervals
interval = pd.interval_range(0, 8, closed='left')

# Display the interval
print("IntervalIndex...")
print(interval)

# Display the interval length
print("\nIntervalIndex length...")
print(interval.length)

# Check if the intervals overlap
print("\nDoes the Intervals that have an open endpoint overlap?")
print(interval.is_overlapping)

IntervalIndex...
IntervalIndex([[0, 1), [1, 2), [2, 3), [3, 4), [4, 5), [5, 6), [6, 7), [7, 8)], dtype='interval[int64, left]')

IntervalIndex length...
Int64Index([1, 1, 1, 1, 1, 1, 1, 1], dtype='int64')

Does the Intervals that have an open endpoint overlap?
False

Example with Overlapping Intervals

Let's create intervals that actually overlap to see the difference ?

import pandas as pd

# Create overlapping intervals
overlapping_intervals = pd.IntervalIndex.from_tuples([(0, 3), (2, 5), (4, 7)])

print("Overlapping IntervalIndex...")
print(overlapping_intervals)

print("\nDo these intervals overlap?")
print(overlapping_intervals.is_overlapping)

Overlapping IntervalIndex...
IntervalIndex([(0, 3], (2, 5], (4, 7]], dtype='interval[int64, right]')

Do these intervals overlap?
True

Key Points

• The is_overlapping property returns False for intervals that only share open endpoints
• Left-closed intervals like [0, 1) and [1, 2) don't overlap because they only share the open endpoint
• True overlapping occurs when intervals share interior points, not just endpoints

Conclusion

The IntervalIndex.is_overlapping property correctly identifies that intervals sharing only open endpoints do not overlap. This is useful for detecting true interval overlaps in time series and range-based data analysis.