user: Question: How many different directors are associated with the writer Gaby Chiappe?
Columns: ['#', 'Episode', 'Writer', 'Director', 'Original air date', 'Viewing figure']
Types: ['real', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, '"Episode 1"', 'Bill Gallagher', 'Charles Palmer', '13January2008', '7.27 million']
SQL:

assistant: SELECT COUNT("Director") FROM "Table" WHERE "Writer" = 'Gaby Chiappe';