用python解包大列表

Question

我必须打开这个大列表，把每一项都放到数据库中。 除了这些数据，一切都很好

我试过：

([styles], [seasons], [day], [id]) = search_

但我得到一个类似这样的错误：

exception=ValueError('too many values to unpack (expected 4)')>

我使用如下查询：

insert= "INSERT INTO cantina (styles,seasons,day,id) VALUES (?,?,?,?)"
db.execute(insert,(styles,seasons,day,id))

我知道我犯了一个错误，但这里每行有4个字段，似乎是对的

search_ = [[["Redwine"], ['04'], ['01'], ['81535']],
[["Redwine"], ['04'], ['02'], ['81536']],
[["Redwine"], ['04'], ['03'], ['81537']],
[["Redwine"], ['04'], ['04'], ['81538']],
[["Redwine"], ['04'], ['05'], ['81539']],
[["Redwine"], ['04'], ['06'], ['81540']],
[["Redwine"], ['04'], ['07'], ['81541']],
[["Redwine"], ['04'], ['08'], ['81542']],
[["Redwine"], ['04'], ['09'], ['81543']],
[["Redwine"], ['04'], ['10'], ['81544']],
[["Redwine"], ['04'], ['11'], ['81545']],
[["Redwine"], ['04'], ['12'], ['81546']],
[["Redwine"], ['02'], ['01'], ['97179']],
[["Redwine"], ['02'], ['02'], ['97180']],
[["Redwine"], ['02'], ['03'], ['97181']],
[["Redwine"], ['02'], ['04'], ['97182']],
[["Redwine"], ['02'], ['05'], ['97183']],
[["Redwine"], ['02'], ['06'], ['97184']],
[["Redwine"], ['02'], ['07'], ['97185']],
[["Redwine"], ['02'], ['08'], ['97186']],
[["Redwine"], ['02'], ['09'], ['97187']],
[["Redwine"], ['02'], ['10'], ['97188']],
[["Redwine"], ['02'], ['11'], ['97189']],
[["Redwine"], ['02'], ['12'], ['97190']]]

([styles], [seasons], [day], [id]) = search_

insert= "INSERT INTO cantina (styles,seasons,day,id) VALUES (?,?,?,?)"
db.execute(insert,(styles,seasons,day,id))

编辑：

嗨，Barmar，因为这个列表来自我加入的另一个函数 四份清单：

def cantina ( cantina_id)
  for ... in ...:
     styles = 
     season  = 
     day = 
     id = 
     result.append([[styles], [season], [day], [id]]])
  return result

“append”只接受一个参数

我必须根据“酒馆id”处理一些数据； 将其添加到四个列表中并保存到db

Answer 1

您需要在search_上循环并分别处理每一行

insert= "INSERT INTO cantina (styles,seasons,day,id) VALUES (?,?,?,?)"
for row in search_:
    ([styles], [seasons], [day], [id]) = row
    cur.execute(insert,(styles,seasons,day,id))
db.commit()

如果更改cantina函数，使其不会创建所有这些单个元素列表，则可以使用executemany()

def cantina ( cantina_id)
  result = []
  for ... in ...:
     styles = 
     season  = 
     day = 
     id = 
     result.append([styles, season, day, id])
  return result

search_ = cantina(some_id)
insert= "INSERT INTO cantina (styles,seasons,day,id) VALUES (?,?,?,?)"
cur.executemany(insert, search_)
db.commit()