user: Question:  how many party with district being Washington 7
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Washington 1', 'Rick White', 'Republican', 1994.0, 'Re-elected', 'Rick White (R) 53.74% Jeff Coopersmith (D) 46.26%']
SQL:

assistant: SELECT COUNT("Party") FROM "Table" WHERE "District" = 'Washington 7';