• 學習資料：
  Python3 Tutorial

1. Interactive Shell

terminal$ python3
>>>

2. Execute .py Script

python fileName.py

Python is both an interpreted and a compiled language.

Python會自動檢查工作目錄的寫權限，如果沒有寫權限，那么編譯的代碼只會在程序執行的時候產生，程序退出，編譯的代碼就會被消除（相當于直接interpret而“未compile”）。如果有寫權限，那么編譯的代碼就會被存在.pyc文件中。

編譯的代碼由PVM執行。

Compiler: to transform source code into executable program

Interpreter: (1) execute the source code directly or (2) translates the source code in a first step into a more efficient representation and executes this code

3. Python structures by colons and indentation

從語法上保證了程序的易讀性

4. Variables

1. Numbers

Integer, Floating, Complex

• There is no "long int" in Python3 anymore, Integers in Python3 can be of unlimited size.
• true div: /; floor div: //

2. String

• All strings in Python 3 are sequences of "pure" Unicode characters

• ASCII: 128 characters
• Unicode: four bytes are possible per character

• Immutable

• 比較

• is 比地址；==比內容
• 一個奇怪之處：

"Hi" is "Hi" == true 
"Hi!" is "Hi!" == False //含特殊字符

5. Operators

10 / 3 == 3.3333333333333335
10 // 3 == 3
10.0 // 3 == 3.0
10**3 == 1000