Python 3 | forループ内で複数のif文を使用していますか？

Question

私は自分のニーズに合ったものを探して見つけました。

私はそれぞれ3つのループを持っていて、その中にそれぞれifの条件があります。コードは次のとおりです。

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)) 

もっと効率的なやり方がありますか？私はそうのようなandオペレータを考えていた：

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)) 

いずれかが同じリストの上に3回反復に並置としてこれを行うための最善あるいは最も効率的な方法を提案することはできますか？

Answer 1

全コード：ここで...きれいなものですForceBruの答えの上に

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)) 
    elif len(columns) == 3: 
     c.execute("""INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `already_friends`) VALUES (?, ?, ?)""", (columns)) 
    elif len(columns) == 2: 
     c.execute("""INSERT INTO `fb_friends`(`name`, `already_friends`) VALUES (?, ?)""", (columns)) 

Answer 2

あなたはif/elif/elseを探しています：ここ

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

Answer 3

は楽しみのための代替です。

d = {2: """INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `already_friends`) VALUES (?, ?, ?)""", 
    3: """INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `already_friends`) VALUES (?, ?, ?)""", 
    4: """INSERT INTO `fb_friends`(`name`, `no_of_mutual_friends`, `no_of_new_posts`, `already_friends`) VALUES (?, ?, ?, ?)"""} 
for friend in friends: 
    columns = friend.split("\n") 
    try: 
     c.execute(d[len(columns)], (columns)) 
    except KeyError: 
     print("you sure about this columns length which was:", len(columns)) 

Answer 4

reqtemplate = "INSERT INTO `fb_friends`(%s) VALUES (%s)" 
fields = ['`name`', '`no_of_mutual_friends`', '`no_of_new_posts`', '`already_friends`'] 
for friend in friends: 
    columns = friend.split("\n") 
    lenc = len(columns) 
    c.execute(reqtemplate % (",".join(fields[:lenc]), ",".join("?" * lenc)), (columns))