【学习笔记】Python基础-数据类型与变量

注释

# hello world

字符串

print("hello world")
print('hello world')

转义符号 \

转义单引号

print("I\'am python")

换行符 \n

print("I\'am python \nI am su")

D:\PythonProject>python helloworld.py
I'am python
I am su

布尔值

print("3 > 5 is ", 3 > 5)
print("3 < 5 is ", 3 < 5)

D:\PythonProject>python helloworld.py
('3 > 5 is ', False)
('3 < 5 is ', True)

注意大小写

print("True or False ", True or False)
print("True and False ", True and False)

D:\PythonProject>python helloworld.py
('True or False ', True)
('True and False ', False)

空值 None

a = None
print(a)

D:\PythonProject>python helloworld.py
None

变量

a = None
print(a)
a = 5
print(a)
a = "hello world"
print(a)

D:\PythonProject>python helloworld.py
None
5
hello world

动态变量

常量

PI = 3.1415
print(PI)

D:\PythonProject>python helloworld.py
3.1415