EasyNLPnlp-109

IOB Consistency Check

Problem

Return True when a tag sequence is valid IOB2: every I-label must follow a B-label or I-label with the same entity type, B- and I- labels are the only allowed entity tags, and O is always allowed.

An empty sequence is valid.

Hint

Track the previous tag and compare entity types on every I- tag.

Test cases

case 1

in: [["B-PER","I-PER","O"]]

expected: true

case 2

in: [["I-PER","O"]]

expected: false

case 3

in: [["B-PER","I-LOC"]]

expected: false

case 4

in: [["O","O"]]

expected: true

case 5

in: [[]]

expected: true

Starter codePython

def iob_consistency_check(tags):
    # Your code here
    pass

5 test cases · run your code against them in the editor