A easy Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

easy

Seniority

L3

Problem

Given a string of lowercase letters, return True if no 'a' appears after any 'b' (once a 'b' is seen, all subsequent chars are not 'a'). Empty strings return True.

Summary

Some rules say every A must come before every B.

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