python基本说明和语法结构

#在python中此处b赋值重新开辟内存地址
a = 1
b = a
a = 2
print(b)

#在python中列表数据类型默认使用引用传递
a = [1,2]
b = a
a.append(3)

print(‘hello word‘)

#条件语句 python用缩进来表示大括号

#一般来讲缩进4个空格 

#并且条件中逻辑若换行 缩进必须一样否则报错

if 条件:

    print(‘1‘)

    print(‘2‘)

elif 条件:

    print(‘3‘)

    print(‘4‘)   

else:条件:

    print(2)

name = ‘master‘

#使用in查找是否包含m
if ‘m‘ in name:
    print(‘is ok‘)
else:
    print(‘is not ok‘)

#not in不包含
if ‘m‘ not in name:
    print(‘is not ok‘)
else:
    print(‘is ok‘)

#返回bool值
print(‘m‘ not in name)

#not取反
print(not True)


user = ‘master‘

#python中用and和or来代表逻辑与 逻辑或
if user == ‘master‘ and ‘mas‘ in user:
    print(‘is ok‘)
else:
    print(‘is not ok‘)

if user == ‘master‘ or ‘mas‘ in user:
    print(‘is ok‘)
else:
    print(‘is not ok‘)

#一个死循环

while 1==1

　　print(‘ok‘)

#while else
count = 10
while count < 10

    print(count)

    count = count + 1 

else 

    print(‘end‘)

#数字

a1 = 10

a2 = 10

#python除了基本的加减乘除 2个乘号代表4的4次方

a3 = 4**4

#取余

a4 = 10 % 2

#两个杠取商

a5=8//3



#常见数字操作

a1 = 2

a2 = 2

a3 = a1 + a2

a3 = a1 - a2

a3 = a1 * a2

a3 = a1 / a2

#次方

a3 = a1**a2

#取商

a3 = a1//a2

#取余

a3 = a1 % a2

inp = input(‘请输入‘)