https://open.163.com/newview/movie/free?pid=MDGEPAQ4K&mid=MDGET74MS https://open.163.com/newview/movie/free?pid=MDGEPAQ4K&mid=MDGET4H0I
冯诺依曼结构 https://open.163.com/newview/movie/free?pid=NGVEDUL25&mid=AGVEDULCA
WINDOWS系统/MacOS系统/Linux系统
增删查改
mkdir C:\workspace\node\blog\Pending\aa echo "C:\workspace\node\blog\Pending\aa\aa.txt">C:\workspace\node\blog\Pending\aa\aa.txt
aa.cmd
https://www.python.org/ 环境变量PATH
- python 1_hello.py\
- IDLE run
- VS Code
x = 4 # x is of type int
x = "Sally" # x is now of type str
print(x)
x = str(3) # x will be '3'
y = int(3) # y will be 3
z = float(3) # z will be 3.0
x, y, z = "Orange", "Banana", "Cherry"
fruits = ["apple", "banana", "cherry"]
x, y, z = fruits
A variable name must start with a letter or the underscore character A variable name cannot start with a number A variable name can only contain alpha-numeric characters and underscores (A-z, 0-9, and _ ) Variable names are case-sensitive (age, Age and AGE are three different variables) A variable name cannot be any of the Python keywords. 参数 第一个字符必须是字母表中字母或下划线'_'。 标识符的其他的部分有字母、数字和下划线组成。 标识符对大小写敏感。
_a a aA aa aa_5 Aa //5asdf
>>> import keyword
>>> keyword.kwlist
['False', 'None', 'True', 'and', 'as', 'assert', 'async', 'await', 'break', 'class', 'continue', 'def', 'del', 'elif', 'else', 'except', 'finally', 'for', 'from', 'global', 'if', 'import', 'in', 'is', 'lambda', 'nonlocal', 'not', 'or', 'pass', 'raise', 'return', 'try', 'while', 'with', 'yield']
>>>
Python 中有六个标准的数据类型:
Number(数字) String(字符串) List(列表) Tuple(元组) Set(集合) Dictionary(字典) Python3 的六个标准数据类型中:
不可变数据(3 个):Number(数字)、String(字符串)、Tuple(元组); 可变数据(3 个):List(列表)、Dictionary(字典)、Set(集合)。
type(x)
word = '字符串' sentence = "这是一个句子。" paragraph = """这是一个段落, 可以由多行组成"""