string 拼接

可以使用 + 實現兩個字串的拼接。

a = "Hello"b = "World"c = a + bprint(c)--- output ---PS E:\dream\markdown\python> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.pyHelloWorld

如果想調整一下格式，可以在 hellworld 之間加上空格，如下所示：

a = "Hello"b = "World"c = a + " " + bprint(c)--- output ---PS E:\dream\markdown\python> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.pyHello World

還記得在前面的文章中提到，將 string 和 int 進行拼接是行不通的，這時候的解決方案就是用 format ,先看一下之前的例子。

age = 36txt = "My name is John, I am " + ageprint(txt)--- output ---PS E:\dream\markdown\python> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.pyTraceback (most recent call last):  File "e:/dream/markdown/python/app/app.py", line 2, in <module>    txt = "My name is John, I am " + ageTypeError: can only concatenate str (not "int") to str

接下來看看 format，在字串中設定一個佔位符 {}，佔位符的引數透過 format 傳入，如下所示：

age = 36txt = "My name is John, and I am {}"print(txt.format(age))PS E:\dream\markdown\python> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.pyMy name is John, and I am 36

有些朋友可能就要問了，既然支援一個 佔位符，那能不能支援多個佔位符呢？ 當然可以啦，如下所示：

quantity = 3itemno = 567price = 49.95myorder = "I want {} pieces of item {} for {} dollars."print(myorder.format(quantity, itemno, price))--- output ---PS E:\dream\markdown\python> & "C:/Program Files (x86)/Python/python.exe" e:/dream/markdown/python/app/app.pyI want 3 pieces of item 567 for 49.95 dollars.

除了這種通用的佔位符，還可以使用類似 C# 中的數字型佔位符形式，實現精準指向性佔位。