入门一：python变量、获取值、标准输出、循环判断语句

　　变量是由字母、数字和下划线组成的，数字不能作为开头。

　　python中没有常量，一般用常量的时候将变量名大写就可以了，注意后面不要修改它的值。

　　变量命令：使用下划线分隔。

　　字符编码在代码开头加入一行

# -*- coding:utf-8 -*-

获取输入的值input：

　　普通输入： 

name = input("name:")
age = int(input("age:"))
job = input("job:")
salary = input("salary:")

　　密文输如：

import getpass

password = getpass.getpass("password:")

标准输出的几种方式：

　　第一种：

info2 = '''
-------------info of {_name}---------
Name:{_name}
Age:{_age}
Job:{_job}
Salary:{_salary}
'''.format(_name=name,
           _age=age,
           _job=job,
           _salary=salary)

　　第二种：

info = '''
--------------------info 0f %s---------------
Name:%s
Age:%d
Job:%s
Salary:%s
'''%(name,name,age,job,salary)

if-else循环

　　猜年龄：

age_of_oldboy = 56

guess_age = int(input("guess age:"))
if guess_age>age_of_oldboy:
    print("your guess is older.")
elif guess_age==age_of_oldboy:
    print("you are right!")
else:
    print("your guess is younger.")

 while循环

　　在猜年龄的基础上控制只让猜三次：

while count<3:
    guess_age = int(input("guess age:"))
    if guess_age>age_of_oldboy:
        print("your guess is older.")
    elif guess_age==age_of_oldboy:
        print("you are right!")
        break
    else:
        print("your guess is younger.")

    count = count + 1
    print("you have {_count} times.".format(_count=3-count))
#if count == 3:
else:
    print("sorry,you try too many times")

for循环：

##基础格式
1 for i in range(1,10,2):
    print("loop ",i)

　　用for循环写猜密码：

age_of_oldboy = 56

for i in range(3):
    guess_age = int(input("guess age:"))
    if guess_age>age_of_oldboy:
        print("your guess is older.")
    elif guess_age==age_of_oldboy:
        print("you are right!")
        break
    else:
        print("your guess is younger.")

    print("you have {_count} times.".format(_count=2-i))
#if count == 3:
else:
    print("fuck")