python 学习分享-基础篇

1、python起手式

写下第一个代码，打印‘hello world’

print('hello world')

2、变量

变量是为了存储信息，在程序中被调用，标识数据名称或类型。

变量定义的规则：

变量名只能是字母，数字或下划线的任意组合

变量名的第一个字符不能是数字

关键字不能生命为变量

为了方便读取等，变量命名一般都遵循变量本身的意义，如名字命名为name，年龄为age等等。

name = "Laay"  #字符串类型string

age = 21  #int类型

province = "shandong"

NameOfTwinsGf = "hanmeimei"

name_of_twins_gf = "hanmeimei"

address = “shanghai”

address1 = address

address = “beijing”   #address1 赋的是值，而不是变量，所以不变

3 注释

#       单行注释，最多不超过80个字符

''' '''   多行注释

4 格式化字符串

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

print("name is :",name)
print("age is :",age)
print("job is :",job)

msg = ''' 
infomation of user %s:
-----------------------------
name:  %s
age :  %d 
job :  %s 
-----------------------------
''' % (name,name,age,job)
print(msg)

5 if else条件

_username = ‘Laay’
_password = ‘Laay’
username = input('input your name :')
password = input('input your password:')
if _username == username and _password == password:
    print('login..')
else:
    print('username or password is correct...')
age = 22
guess_num = int(input('input your num:'))
if guess_num == age :
    print('congratulations! you got it.')
elif guess_num >age:
    print('think smaller!')
else:
    print('think bigger!')

6 while 循环

age = 22
counter = 0 
for i in range(10)
    if counter<3:
        guess_num = int(input('input your num:'))
        if guess_num == age :
            print('congratulations! you got it.')
            break
        elif guess_num >age:        
            print('think smaller!')
        else:
           print('think bigger!')
    else:
        continue_confirm = input('Do you want to contnue because you are stupid:')
        if countinue_confirm == 'y'
            counter   =  0
            ciontinue
        else:
            print('bye')
            break
    count + = 1