String formatting output, the while loop, operators, encoding

1. String formatted output

• % Placeholders:% s => D = String%> = Integer %%> Common escape%% () no more, no less, one-
• f "{}" braces are generally put the contents of variables, string single quotes '' version 3.6 and above to use

2.while cycle

while  条件：
       循环体（死循环）
       break（终止当前的循环）
       continue (跳出本次循环，继续下次循环)

3. Operator

• Arithmetic operators + - * /% (remainder) ** (power) // (divisible)

• Assignment Operators

  a=1
  a+=1  => a=a+1
  a-=1  => a=a-1
  a*=1  => a=a*1
  a/=1  => a=a/1
  a**=1  => a=a**1
  a%=1  => a=a%1
  a//=1  => a=a//1

• Logical operators and or not (priority :(), not, and, or)

• Comparison operator ==! = (Not equal)> <> = <=

• Member operator in not in

4. encoding

• ASCII code is not supported by Chinese

• GBK (GB) English one-byte Chinese 2 bytes

• Unicode (Unicode) English 2 bytes 4 bytes Chinese

  utf-8 (the most popular encoding) English 1 byte 2 bytes Europe Asia 3 bytes

• Unit conversion:

  1B=8b
  1024B=1KB
  1024KB=1MB
  1024MB=1GB
  1024GB=1TB