A .while loop

1. Basic loop (infinite loop)

while 条件:
    循环体

2. Using while counting

count = 0               # 数字里面非零的都为True
while True:
    count = count + 1
    print(count)

3. The number of times while the control loop

count = 0
while count < 100:
    count = count + 1
    print(count)
    
# 打断循环的方式
1.自己修改条件
2.使用break关键字

4.break keyword

break-- terminate the current cycle, the code below will not be executed.

num = 1
while num < 6:
    print(num)
    num = num + 1
    break
    print("end")

5.continue keyword

continue-- temporarily as a last line of code in the loop body (jump out when the cycle continues next cycle), the following code will not be executed.

num = 1
while num < 6:
    print(num)
    num = num + 1
    countinue
    print("end")
    
# break和continue的相同之处:他们以下的代码都不会被执行

6.while else

# 循环一
while True:
    if 3 > 2:
        print("你好")
        break
else:
    print("不好")
    
# 循环二
while True:
    if 3 > 2:
        print("你好")
print("不好")

II. Formatted output

Formatting a string passed by ordinal position, and occupying fill bits must be one correspondence.

%---占位
%s---是占的字符串类型的位置
%d(%i)---是占的数字类型的位置
%%---转换成普通的%



a = "------------- info -------------"
b = "name:"
c = "age:"
d = "job:"
e = "-------------- end -------------"
name = input("name")
age = input("age")
job = input("job")
print(a + "\n" + b + name + "\n" + c + age + "\n"+ d + job + "\n" +e)

# %d 数字类型
num = input('学习进度：')
s11 = "大哥黑的学习进度为:%s %%"
print(s11%(num)

# %s 字符串类型
s = """ ------------- info -------------
name:%s
age:%s
job:%s
-------------- end -------------
"""
name = input("name")
age = int(input("age"))
job = input("job")
print(s%(name,age,job))



# 其他方式      
s = f"今天下雨了{input('>>>')}"
print(s)
      
s = f"{1}{2}{3}"
print(s)

III. Operator

1. The arithmetic operators

Suppose a = 10, b = 20

Operators	description	Examples
+	plus	a+b #30
-	Less	a-b #-10
*	Multiply	a*b # 200
/	except	b/a #2
%	Modulo (the number of remainder)	b%a #0
**	power	a**b #10000000000000000
//	Divisible (except flooring)	20//10 #2.0

2. Comparison Operators

Operators	description
==	equal
!=	not equal to
>	more than the
<	Less than
>=	greater or equal to
<=	Less than or equal

3. assignment operator

Operators	description
=	Simple assignment operator
+=	Addition assignment operator
-=	Subtraction assignment operator
*=	Multiplication assignment operator
/=	Division assignment operator
%=	Modulo assignment operator
**=	Power assignment operator
//=	Assignment operator take divisible

4. Logical Operators

Operators	description
and	And / and
or	or
not	non-

逻辑运算的顺序排列:从左往右开始执行
    ()  >  not  >  and   > or
               and             or             一真一假
 都为真:      取后面的          取前面的           取假的
 都为假:      取前面的          去后面的           取真的
    
not True:  False
not False:  True

The member operator

in     --  存在
not in --  不存在

IV. Acquaintance coding (coding set)

1.ASCII (United States)

Does not support Chinese

2.GBK (GB)

English --8 bit 1 byte

Chinese --16 bytes 2 bits

3.Unicode (Unicode)

Byte 2 Bit English --16

Chinese --32 bit byte 4

4.Utf-8