Python Pandas - Check whether the interval is closed on the left-side, right-side, both or neither

To check whether a Pandas interval is closed on the left-side, right-side, both or neither, use the interval.closed property. This property returns a string indicating the closure type of the interval.

Understanding Interval Closure Types

Pandas intervals can have four types of closure:

• both ? Closed on both sides [a, b] (includes both endpoints)
• left ? Closed on left only [a, b) (includes left endpoint only)
• right ? Closed on right only (a, b] (includes right endpoint only)
• neither ? Open interval (a, b) (excludes both endpoints)

Example: Checking Interval Closure

Let's create different types of intervals and check their closure properties ?

import pandas as pd

# Create intervals with different closure types
interval_both = pd.Interval(left=0, right=20, closed='both')
interval_left = pd.Interval(left=0, right=20, closed='left') 
interval_right = pd.Interval(left=0, right=20, closed='right')
interval_neither = pd.Interval(left=0, right=20, closed='neither')

# Display intervals and their closure types
print("Interval (both):", interval_both)
print("Closure type:", interval_both.closed)
print()

print("Interval (left):", interval_left)  
print("Closure type:", interval_left.closed)
print()

print("Interval (right):", interval_right)
print("Closure type:", interval_right.closed)
print()

print("Interval (neither):", interval_neither)
print("Closure type:", interval_neither.closed)

Interval (both): [0, 20]
Closure type: both

Interval (left): [0, 20)
Closure type: left

Interval (right): (0, 20]
Closure type: right

Interval (neither): (0, 20)
Closure type: neither

Testing Endpoint Inclusion

You can verify the closure behavior by checking if endpoints are included in the interval ?

import pandas as pd

# Create a closed interval on both sides
interval = pd.Interval(left=0, right=20, closed='both')

print("Interval:", interval)
print("Closure type:", interval.closed)
print()

# Test endpoint inclusion
print("Left endpoint (0) in interval:", 0 in interval)
print("Right endpoint (20) in interval:", 20 in interval)
print("Middle value (10) in interval:", 10 in interval)

Interval: [0, 20]
Closure type: both

Left endpoint (0) in interval: True
Right endpoint (20) in interval: True
Middle value (10) in interval: True

Comparison of Closure Types

Conclusion

The closed property is essential for understanding interval boundaries in Pandas. Use it to determine which endpoints are included when working with interval-based operations and filtering.