python 3 |在 for 循环中使用多个 if 语句？

Question

我已经搜索过，但没有找到适合我需要的东西。

我有三个 for 循环，每个循环中都有一个 if 条件。这是代码:

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))

有没有更有效的方法？我在想这样的 和 运算符:

 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))

除了在同一个列表上迭代 3 次之外，有谁能提出最好或最有效的方法吗？

Answer 1

你正在寻找if/elif/else:

if len(smth) == 5:
    # do this
elif len(smth) == 6:
    # do that
else:
    # do something else