一 打印
print("xxx")
二 变量/字符串
（一）变量作用
用于存储东西以便之后调用
（二）变量定义
1 变量的操作
name ="Tortoise man"
print("My name is",name)
name2 =name
print("My name is",name,name2)
name ="X"
print(name,name2)
此时的name != name2
2 定义的规则
- 变量名只能是字母、数字或下划线的任意组合
- 变量名的首字母不能是数字
- python关键词不能为变量（and,while,print et al.）
三 字符编码
ASCII 255=2^8-1 1byte
GB2312 7XXX
GBK1.0 2W+
GB18030 27XXX
Unicode 2bytes
utf-8 English: 1byte, Chinese：3bytes
四 注释
(一) 单行注释
#XXX
(二) 多行注释
'XXX' or "XXX"
五 用户输入
（一）简单输入
username=input("username:")
password=input("password:")
（二）格式化输出
1 info
name =input("name:")
age =input("age:")
job =input("job")
salary =input("salary")
info='''
-------info of %s----
name =%s
age =%d
job =%s
salary =%s
'''%(name,age,job,salary)
print(info)
2 info2
name =input("name:")
age =input("age:")
job =input("job")
salary =input("salary")
info2 ='''
------info of {_name}-----
name ={_name}
age ={_age}
job ={_job}
salary ={_salary}
'''.format (_name =name,
_age=age,
_job=job,
_salary=salary)
print(info2)
3 info3
name =input("name:")
age =input("age:")
job =input("job")
salary =input("salary")
info3='''
-----info of {0}-----
name={0}
age={1}
job={2}
salary={3}
'''.format(name,age,job,salary)
print(info3)
note A:打印输入类型
print(type("X"))
note B:字符变数字
int(print("X"))
六 密码明文变密文
import getpass
username = import(“username:”)
password =getpass.getpass (“password:”)
七 认证用户和密码
_username = input(“username:”)
_password =input (“password:”)
If _username == username and _password == password:
Print(“welcome user (name) login….”)
Else:
Print(“invalid username or password!”)
八 猜数字
age_of _oldboy = 56
guess_age = int(input(“guess age:”))
if guess_age ==age_of_oldboy:
print(“yes,you got it”)
elif guess_age>age_of_oldboy:
print(“think smaller…”)
else:
print(“think bigger!”)
九 while循环
（一）循环到1000
count = 0
while True:
print(“count:”,count)
count = count +1
If count == 1000:
Break
（二）正确后退出
age_of _oldboy = 56
while true:
guess_age = int(input(“guess age:”))
if guess_age ==age_of_oldboy:
print(“yes,you got it”)
break
elif guess_age>age_of_oldboy:
print(“think smaller…”)
else:
print(“think bigger!”)
（三）循环恰好三次退出
age_of _oldboy = 56
count = 0
while true:
if count == 3:
break
guess_age = int(input(“guess age:”))
if guess_age ==age_of_oldboy:
print(“yes,you got it”)
break
elif guess_age>age_of_oldboy:
print(“think smaller…”)
else:
print(“think bigger!”)
count =count+1
age_of _oldboy = 56
count = 0
while count<3:
guess_age = int(input(“guess age:”))
if guess_age ==age_of_oldboy:
print(“yes,you got it”)
break
elif guess_age>age_of_oldboy:
print(“think smaller…”)
else:
print(“think bigger!”)
count =count+ 1
（四）尝试多次之后提醒
age_of _oldboy = 56
count = 0
while true:
if count<3:
guess_age = int(input(“guess age:”))
if guess_age ==age_of_oldboy:
print(“yes,you got it”)
break
elif guess_age>age_of_oldboy:
print(“think smaller…”)
count=count+ 1
else:
print(“you have tried too many times….”)
（五）3次之后提醒是否继续
age_of_oldboy = 56
count = 0
while count <3:
guess_age = int(input("guess age:") )
if guess_age == age_of_oldboy :
print("yes, you got it. ")
break
elif guess_age > age_of_oldboy:
print("think smaller...")
else:
print("think bigger!")
count +=1
if count == 3:
countine_confirm = input("do you want to keep guessing..?")
if countine_confirm != 'n':
count =0
十 for循环
（一）连续打印
for i in range(10):
print(“loop”,i)
（二）跳行打印
for i in range(0,10,2):
print(“loop”,i)
十一 while循环变for循环
age_of _oldboy = 56
for i in range(3):
guess_age = int(input(“guess age:”))
if guess_age ==age_of_oldboy:
print(“yes,you got it”)
break
elif guess_age>age_of_oldboy:
print(“think smaller…”)
else:
print(“you have tried too many times….”)
十二 contine（跳出本循环，跳到下一个循环）
for I in range(0,10):
If i<3:
print(“loop”,i)
else:
continue
print(“hehe…”)
十三 循环嵌套
for i in range(10):
print(“loop”,i)
for j in range(10):
print(j)
if j>5
break