A vowel is treated here as one of the letters a, e, i, o, or u. The programming exercises use this letter-based rule as an approximation of vowel sounds. section 3.10
Use vowels when implementing string transformations:
- Test membership with `word[0] in 'aeiou'` instead of repeating comparisons or writing a manual search loop. section 3.3
- Scan each character when every vowel must trigger an insertion, adding `ub` before vowels while leaving other letters unchanged. section 3.11
- Treat adjacent vowels independently in the simplified exercise, even when they might represent one sound. section 3.10
Ubbi Dubbi
Applying `ub` before each vowel transforms `milk` into `mubilk`, `program` into `prubogrubam`, and `soap` into `suboubap`. section 3.10
if word[0] in 'aeiou':
The compact membership test demonstrates the idiomatic Python strategy for checking whether a character is a vowel. section 3.3
