09-Data type

09-Data type

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1: Commonly used data types

type of data	express	Example
integer	int	2, 3, 45 etc.
floating point number	float	1.5, 2.5, 3.5 etc.
Boolean	bool	true, flase
string	str	Life is short, I use Python

2: Integer type

• English integer, abbreviated as int, can represent positive numbers, negative numbers and zero

• Integers are expressed in different bases:

  base	basic number	Every time I enter	Representation
  decimal	0，1，2，3，4，5，6，7，8，9	10	520
  binary	0，1	2	0b1000001000
  Octal	0，1，2，3，4，5，6，7	8	0o1010
  hexadecimal	0，1，2，3，4，5，6，7，8，9，A，B，C，D，E，F	16	0x208

• Demo:

  print("十进制: ",520)
  print("二进制: ",0b1000001000)
  print("八进制: ",0o1010)
  print("十六进制: ",0x208)
  

  Output:

  520
  520
  520
  520
  

Three: Floating point type

• Floating point numbers consist of an integer part and a decimal part

• The storage of floating point numbers is inaccurate and the calculations are biased because the computer uses binary storage.

  Solution:

  from decimal import Decimal  #导入模块
  print(Decimal('1.1')+Decimal('2.2'))
  

  3.3
  

Four: Boolean type

• Values ​​used to represent true and false
• Boolean can be converted to integer, True→1, False→2

Five: String type

• String is also known as immutable sequence of characters

• Can be defined using ‘ ‘, " “,”’ '"

• Strings defined by single quotes and double quotes must be on one line, and strings defined by triple quotes can be distributed on multiple consecutive lines.

• Demo:

  s1 = 'Hello'
  s2 = ("hello"
        "word")
  s3 = '''hello
  word'''
  print(s1)
  print(s2)
  print(s3)
  

  Output:

  Hello
  helloword
  hello
  word