Search for a list in database psql

i have a table user: id, name, user-name. its around 20000000 rows.
i have a list of name which i need to select all data name id and user-name but only if name in the list. the list length i about 6000. this is the code but one by one it take long time to complete!!.

data = []
for i in range(0,len(name_list)):
cur.execute(
'SELECT user.name, id, user-name,FROM user WHERE name = %s,
(name_list)
)

m = cur.fetchall()
data.append(m)