Python Pandas IntervalIndex - Check if an interval that contains points is empty or not

To check if an interval that contains points is empty or not, use the IntervalIndex.is_empty property in Pandas. This property returns a boolean array indicating whether each interval in the IntervalIndex is empty.

What is an Empty Interval?

An interval is considered empty when its left and right bounds are equal, meaning it contains no points. For example, an interval like [5, 5) is empty because it has no width.

Creating IntervalIndex

Let's start by creating an IntervalIndex with some intervals ?

import pandas as pd

# Create IntervalIndex with non-empty intervals
interval = pd.IntervalIndex.from_arrays([0, 1], [1, 2], closed='right')
print("IntervalIndex...")
print(interval)

IntervalIndex...
IntervalIndex([(0, 1], (1, 2]], dtype='interval[int64, right]')

Checking if Intervals are Empty

Use the is_empty property to check if intervals contain points ?

import pandas as pd

# Create IntervalIndex with non-empty intervals
interval = pd.IntervalIndex.from_arrays([0, 1], [1, 2], closed='right')

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

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

# Check if the interval that contains points is empty or not
print("\nIs the interval empty?")
print(interval.is_empty)

IntervalIndex...
IntervalIndex([(0, 1], (1, 2]], dtype='interval[int64, right]')

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

Is the interval empty?
[False False]

Example with Empty Intervals

Let's create an IntervalIndex that includes empty intervals ?

import pandas as pd

# Create IntervalIndex with some empty intervals
interval = pd.IntervalIndex.from_arrays([0, 2, 3], [1, 2, 5], closed='left')

print("IntervalIndex...")
print(interval)

print("\nInterval lengths...")
print(interval.length)

print("\nIs the interval empty?")
print(interval.is_empty)

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

Interval lengths...
Index([1, 0, 2], dtype='int64')

Is the interval empty?
[False  True False]

Conclusion

The is_empty property returns a boolean array indicating which intervals are empty. An interval is empty when its left and right bounds are equal, resulting in zero length.