python基础

Posted 2020-10-20 bai-jun

1.变量

变量名可以包括字母、数字、下划线，但是数字不能做为开头

系统关键字不能做变量名使用

除了下划线之个，其它符号不能做为变量名使用

Python的变量名是除分大小写的

2.字符编码

Python 2 里面需要指定字符编码,(python 3 不需要)

# -*- coding:utf-8 -*-
#Author:Bai
name = "你好，世界"
print (name)

3. 注释

3.1单行注释

单行注释用#注释

3.2多行注释

多行注释用’’’ ‘’’进行注释

可以用来定义多行变量用法：

msg = ‘‘‘

name = "你好，世界"

world = "china"

print (name)

‘‘‘

print (msg)

4.用户输入

#Author:Bai

name = input ("name:")

age = int(input ("age:"))

print (type(age))

job = input ("job:")

salary = input ("salary:")



info = ‘‘‘

------ info of %s ----

name:%s

age:%d

job:%s

salary:%s

‘‘‘ % (name,name,age,job,salary)

print (info)



info2 = ‘‘‘

------ info of {_name} ----

name:{_name}

age:{_age}

job:{_job}

salary:{_salary}

‘‘‘.format(_name=name,

           _age=age,

           _job=job,

           _salary=salary

)

print (info2)

5.while循环

age_of_oldboy = 45

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

else:

    print("you try too many time.get off")

 

6.for循环

for i in range(10):
    print(‘----‘,i)
    for j in range(10):
        print(j)
        if j >5:
            break