python base (while, operators, encoded initial)

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while循环

while loop

Loop: something that is constantly repeated cycle

while keywords

Infinite loop: while True:

Loop

while True: # 死循环#

print("坚强")#

print("过火")#

print("单身情歌")#

print("郭德纲的小曲")#

print("五环之歌")#

print("鸡你太美")#

print("大碗宽面")#

print("痒")

while the structure:

while conditions:

Indent loop

Control cycles: cycle number by controlling conditions

count = 0#

while True: # 死循环#

count = count + 1 # 先执行 = 右边的内容#

if count == 5:#

print(count)#

break # 有限循环

while loop in two keywords:
- break: terminate this cycle
- continue: out of this cycle, the next cycle continues (disguised as the last line of the loop)
- continue and break below the code will not be executed
while else
- while else and if else similar
- structure:
  
  while conditions:
  
  Indent loop
  
  else：
  
  Indent results

format

% S string:% is a placeholder, s represents the percentage contents into a string, you can fill in the numbers, or fill in a string
% D |% i: must be filled with digital
%% Escape: become common%
msg = "mountain brother, the current learning progress is% s %%"

print(msg%(2))
- Order of position correspondence (accounting for several positions to fill several positions)

f-string python3.6 version and above to use

a =1b =2msg = f"my name is {a} I'm {b} years old"print(msg)

Operators

Comparison Operators

#  >  <  >=  <=  ==(等于) != (不等于)

Arithmetic Operators

# + - * /
# //(整除|地板除(向下取整))
# ** 幂# % 取余(模)
# print(5 / 2)  
# 2.5
# print(5 // 2)
# 2
# print(2 ** 0)
# 1
# print(5 % 2)  
# 1

Assignment Operators

#     =
#     +=
#     -=#     *=
#     /=#     //=
#     **=
#     %= 
# a = 10
# b = 2
# b += 1 
# b = b + 1
# print(b)
# a -= 1  
# a = a - 1
# a *= 2  
# a = a * 2
# a /= 2  
# a = a / 2
# a //= 2 
# a = a // 2
# a **= 2 
# a = a ** 2
# a %= 2  
# a = a % 2

Logical Operators
- Take back and sides are true, or take the front, sides are false, and taking the front, back or takes and: to give a false false
  
  or: a really really
```
# 与(and 并且) 或(or) 非(not 不是)
# True and False
# True or False
# True and not False
# 优先级:() > not > and > or 
# 查找顺序: 从左向右
```

Member operator

# in(在)    not in(不在)
# name = "alex"
# msg = input(">>>")
# if name in msg:
#     print(111)
# else:
#     print(222)

The initial coding

# 编码集(密码本)
# ascii  不支持中文
#   a 一个字符占用8位
# gbk(包含ascii)国标
#    a 一个字符占用8位(1字节)
#   中文 一个字符占16位(2字节)
# unicode# 英文  4个字节  32位
# 中文  4个字节  32位
# utf-8 (最流行的编码集)
# 英文 1字节      8位
# 欧洲 2字节      16位
# 亚洲 3字节      24位
# 单位转换:    # 1字节 = 8位       *****    
# 1Bytes = 8bit    *****    
# 1024bytes = 1KB    
# 1024KB = 1MB    
# 1024MB = 1GB    
# 1024GB = 1TB  # 够用了    
# 1024TB = 1PB

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while循环