user: Question: What was the constructor of the car that Achille Varzi drove before 1937?
Columns: ['Year', 'Driver', 'Constructor', 'Location', 'Report']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1940.0, 'Giuseppe Farina', 'Alfa Romeo', 'Mellaha', 'Report']
SQL:

assistant: SELECT "Constructor" FROM "Table" WHERE "Year" < 1937.0 AND "Driver" = 'Achille Varzi';