user: Question: How many co-singers were there when Parveen Babi co-starred?
Columns: ['Song', 'Singer', 'Co-Singers', 'Music Director', 'Lyricist', 'Co-Stars', 'Movie/Album', 'Year', 'Additional Info']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text', 'real', 'text']
Sample row: ['Holi Hai Holi Sakhi', 'Asha Bhosle', 'N/A', 'Madan Mohan Kohli', 'Rajendra Krishan', 'Cuckoo', 'Khota Paisa', 1958.0, 'Jogi or Sanyasi']
SQL:

assistant: SELECT COUNT("Co-Singers") FROM "Table" WHERE "Co-Stars" = 'Parveen Babi';