在寫 python 程式碼時，有時變數值是一個非常長的字串，比如這樣：

line = 'this is a very very very very very very very very very very long string'

如果寫在一行裡，難看不說，可能還過不了一些程式碼風格檢測。

那麼應該怎麼折行呢？

方案1

line = """
this is a very very very very
very very very very very very
very very very very very very
long string
"""

但是這個方案有個弊端，本來是一行字串，結果變成了多行，而且如果有縮排的話，本來表示縮排的空格，也作為字串的一部分了。跟我們實際想要的並不一致。

方案2

line = 'this is a\
very very very
long string 
'

此方案解決了方案1裡多餘的換行符的問題，字串真的是一行了。但是同樣沒解決縮排導致的多餘的空格的問題

方案3

line = (
    "this is a"
    "very very very very"
    "long string"
)

此方案完美地解決了長字串 折行/換行 的問題。
另外強調一下，如果有格式化字串需求的話，應該這麼寫：

a = "test_str"
b = 123
line = (
    "i have a string %s"
    "and a number %d"
) % (a, b)
 

媽媽再也不用擔心我的一行程式碼太長了