CREATE TABLE table_30977 ("Season no." FLOAT, "Series no." FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" FLOAT, "U.S. viewers  ( millions ) " TEXT)

How many episodes were written by Warren Leight?
SELECT COUNT("Season no.") FROM table_30977 WHERE "Written by" = 'Warren Leight'
SELECT COUNT("Season no.") FROM "table_30977" WHERE "Written by" = 'Warren Leight'