我搜查了一下,找不到適合我需求的東西。Python 3 |在for循環中使用多個if語句?
我有三個for
循環,其中每個都有if
條件。這裏是代碼:
for friend in friends:
columns = friend.split("\n")
if len(columns) == 4:
c.execute("""INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `no_of_new_posts`, `already_friends`) VALUES (?, ?, ?, ?)""", (columns))
for friend in friends:
columns = friend.split("\n")
if len(columns) == 3:
c.execute("""INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `already_friends`) VALUES (?, ?, ?)""", (columns))
for friend in friends:
columns = friend.split("\n")
if len(columns) == 2:
c.execute("""INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `already_friends`) VALUES (?, ?, ?)""", (columns))
有沒有更有效的方式做到這一點?我在想and
運營商,像這樣:
for friend in friends:
columns = friend.split("\n")
if len(columns) == 4:
c.execute("""INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `no_of_new_posts`, `already_friends`) VALUES (?, ?, ?, ?)""", (columns))
and
if len(columns) == 3:
c.execute("""INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `already_friends`) VALUES (?, ?, ?)""", (columns))
and
if len(columns) == 2:
c.execute("""INSERT INTO `fb_friends`(`name`, `already_friends`) VALUES (?, ?)""", (columns))
任何一個可以表明這樣做的最好,最有效的方式,以並列在同一目錄遍歷三次?
if語句和墊'columns'大小4相反,你可以迴避:'列+ [無] *(4-LEN(列))' – jfs
我找到你的'(列)使用**非常**誤導。它什麼都不做(你可以用'columns'替換'(columns)',並且什麼都不會改變),但它與創建一個元素元組的'(columns,)'(注意最後的逗號!)類似。 – Bakuriu