Data types and common operators in Python

I. Data types common in Python

1. Integer: The operation is accurate at any time

2. Floating-point number: When the operation, there may be rounding

3. String: string is any text enclosed in single quotation mark ' or double quotation mark '

1) The same type can be used with the + number or, the number for splicing

2) Different types can only use, number splicing, can not use the + number

3) After casting, can be splicing, such as STR (a) int (a) this is the cast

4. Boolean: Boolean value only true, false two values, the result of the logical operation is a Boolean value

5. Value of None: null is a special value in Python, represented by none, none is not understood as 0, because 0 is meaningful, and none is a special empty object

• Note: There is no null in Python
• The empty string is different from the none value, and the empty string is ""

two. The operators commonly used in Python

Arithmetic operators

Compare (relational) operators

Assignment operators

logical operators

Bitwise operators

Member operators

Identity operator

1. Arithmetic Operators

As the following table, suppose A = ten, B = 20

Operator	Describe	Instance
+	Add: Two objects added	A + B output result 30
-	Minus: One number minus another number	-B Output Result-10
*	Multiply by: Two number multiplied or returns a string that repeats several times	A * b output result 200
/	Except: x divided by Y	B/A Output Results 2.0
%	Modulo: Returns the remainder of a division	B% A output result 0
**	Power: Returns the Y power of X	A * * b is 10 of 20 output result 100000000000000000000
//	Divide: Returns the integer part of the result	9//2 output result 4, 9.0//2.0 Output Result 4.0

Here, we should pay extra attention to, in Python3,/is True division, get at least one bit of the decimal, and in Python2/means rounding

10/5 results:2.0

Although it represents rounding, if any of the divisor and dividend is a floating-point number, the resulting result is also a floating-point number

5//35.0//+//3.05.0//3.0 results:11.01.01.0

2. Comparison Operators

As the following table, suppose A = ten, B = 20, the return value is a Boolean value

Operator	Describe	Instance
==	equals: Compares objects for equality	(A = = b) returns False
!=	Not equal to: Compares two objects for unequal	(A! = b) returns True
>	Greater than: Returns whether x is greater than Y	(A > B) return False
<	Less than: Returns whether x is less than Y. All comparison operators return 1 for true, and return 0 for false. This is different with the special variable True and false are equivalent. Note that the capitalization of these variable names	(A < b) returns true
>=	Greater than or equal to: Returns whether x is greater than or equal to Y	(a >= b) returns False
<=	Less than equals: Returns whether x is less than or equal to Y	(a <= b) returns True

The comparison operator returns a Boolean value, and the assignment is different from = =, please note!

3. Assignment Operators

As the following table, suppose A = ten, B = 20

Operator	Describe	Instance
=	Simple assignment operator	c = A + B assigns the result of the operation of A + B to c
+=	Addition assignment operator	c + = A is equivalent to C = C + A
-=	Subtraction assignment operator	C-= A is equivalent to C = c-a
*=	Multiplication assignment operator	C *= A is equivalent to C = c * A
/=	Division assignment operator	C/= A is equivalent to C = c/a
%=	Modulo assignment operator	C%= A is equivalent to C = c% A
**=	Power assignment operator	c * * = A is equivalent to C = c * * A
//=	Take the divisible assignment operator	C//= A is equivalent to C = c//A

+ = and-= are more commonly used operators

Data types and common operators in Python