Parsing the Infamous Japanese Postal CSV

Japan Post's postal code CSV file (ken_all.csv) is notoriously difficult to parse due to multiple design flaws, including meaningless parenthetical notes, arbitrary line breaks for fields exceeding character limits (38 characters for neighborhood names, 76 for katakana pronunciation), and inconsistent break points that don't align with word boundaries. The author created the posuto package to make this widely-used but poorly-formatted postal data more accessible to users.