1、变量
a、类型:
描述:就如调料罐子,专门的罐子放专门的佐料。盐、味精、油放在不同的容器而已,容器也有大小之分(类型转换)
# -*- coding:utf-8 -*-
# Author:chenpi
name = "chenpi"
name1=name
print(name," is a name")
name = "jiege"
print(name,name1)
原理:name通过引用指向了内存中 "chenpi"在内存中的地址0xxx,把name的地址赋给了name1,所以name1 的地址变成了"chenpi"在内存中的地址,所以当name改变了新的引用并不会影响到name1值的改变,因为两个变量所指的内存地址不一样。
b、变量名
下划线
驼峰
c、变量的使用
2、常量
a、变量名
大写:PIE
3、字符编码
二进制:
2**n -1
128 = 2**7-1
a、ascii码
b、GB2312 1980
c、GBK 1995
d、GB18030 2000
e、Unicode #兼容所有中文,万国码
f、UTF-8 可变长的Unicode #en:1byte zh:3byte
注意:python2和python3有个小区别!
八进制
十六进制
4、用户交互
2.x
row_input:
input:输入是什么就是什么 #没有引号那输入就是变量,有引号就是字符串
3.x
input:
5、类型转换
int(input(“something !”))
string(input(“something !”))
6、
流程控制:
if... else
if... elif ... else
while
for
switch ... case:
#continue
#break
eg:if..elif...else
# -*- coding:utf-8 -*- # Author:chenpi age_of_chenpi = 18 guess_age = int(input("you guess age:")) if guess_age == age_of_chenpi: print("Congrauation you guess right!!") elif guess_age > age_of_chenpi: print("think bigger !") else: print("think smaller...")
eg:while
# -*- coding:utf-8 -*- # Author:chenpi count = 0 age_of_chenpi = 18 while count < 3: guess_age = int(input("you guess age:")) if guess_age == age_of_chenpi: print("Congrauation you guess right!!") break elif guess_age > age_of_chenpi: print("think bigger !") else: print("think smaller...") count +=1 else: print("you have tried to many times ...fuck off !")
eg:for
# -*- coding:utf-8 -*- # Author:chenpi for i in range(10): print("----------",i) for j in range(10): print(j) if j >5: break