python - 有一个更好的方法吗？

Question

我有一个包含“cellid”、“date”(日期时间)和“block”(真实)列的表格。

我正在尝试查找过去 3 天内 block > 1 的所有 ID。

我目前是这样做的:

cells = npar.db.execute("SELECT cellid FROM data WHERE block > 1 AND date=?", (files[0][1],)).fetchall()
cells1 = npar.db.execute("SELECT cellid FROM data WHERE block >1 AND date = ?", (files[1][1],)).fetchall()
self.common(cells,cells1)
cells1 = npar.db.execute("SELECT cellid FROM data WHERE block >1 AND date = ?", (files[2][1],)).fetchall()
self.common(cells,cells1)

print len(cells)
def common(self,a,b):
    for item in a:
            if item not in b:
                a.remove(item)

b = npar.db.execute("SELECT cellid FROM data WHERE block > 1 AND date >= ? GROUP BY cellid HAVING COUNT(cellid) = 3", (files[2][1],)).fetchall()
        print len(b)

len(b) 不等于 len(cells)

Answer 1

“过去 3 天”？那么以下方法可行吗？

cells = npar.db.execute("SELECT cellid FROM data "
                        "WHERE block > 1 "
                        "AND date >= ? "
                        "GROUP BY cellid "
                        "HAVING COUNT(*) = 3", (files[0][1],)).fetchall()