Operators

Init

• python에서는 7개 그룹의 연산자가 있음
  • Arithmetic operators
  • Assignment operators
  • Comparison operators
  • Logical operators
  • Identity operators
  • Membership operators
  • Bitwise operators

Arithmetic Operators

• 산술 연산.

Operator	Name	Example
+	Addition	2 + 3 = 5
-	Subtraction	3 - 2 = 1
*	Multiplication	2 * 3 = 6
/	Division	5 / 2 = 2.5
%	Modulus	7 % 2 = 1
**	Exponentiation	2 ** 3 = 8
//	Floor division	10 // 3 = 3

Comparison Operators

• 비교연산

Operator	Name	Example
==	Equal to	2 == 2
!=	Not equal to	2 != 3
<	Less than	2 < 3
>	Greater than	3 > 2
<=	Less than or equal to	2 <= 3
>=	Greater than or equal to	3 >= 2

Logical Operators

• 논리 연산

Operator	Name	Example
and	Logical AND	x > 5 and x < 10
or	Logical OR	x < 5 or x > 10
not	Logical NOT	not(x > 5 and x < 10)

Assignment Operators

• 할당연산

Operator	Example	Same as
=	x = 5	x = 5
+=	x += 3	x = x + 3
-=	x -= 3	x = x - 3
*=	x *= 3	x = x * 3
/=	x /= 3	x = x / 3
%=	x %= 3	x = x % 3
//=	x //= 3	x = x // 3
**=	x **= 3	x = x ** 3
&=	x &= 3	x = x & 3
|=	x |= 3	x = x | 3
^=	x ^= 3	x = x ^ 3
»=	x »= 3	x = x » 3
«=	x «= 3	x = x « 3

Identity Operators

• 항등연산
• object 비교.
• 같은 object가 아닌
  같은 memory에 있는
  object인지 비교.

Operator	Example	Result
is	x is y	Returns True if the same object
is not	x is not y	Returns True if not the same object

Membership Operators

• 멤버쉡 연산
• object에 시퀀스가 존재하는지 테스트.

• Operator	Example	Name
  in	x in y	Returns True if y have x
  not in	x not in y	Returns True if y have not x

• 아무튼 좀 애매한부분을 더 봤는데

  l2 = [1, 2, 3]
  l3 = [1, 2]
  item = 3
    
  print("l1 in l2 ?", (l1 in l2))
    
  print("item in l1 ?", (item in l1))
    
  print("l3 in l1 ?", (l3 in l1))
  

  l1 in l2 ? False
  item in l1 ? True
  l3 in l1 ? False
  

  해서, 집합기호로 따지면 ∈ 관계.
  부분집합이 아닌 원소.

Bitwise Operators

• 비트연산

Operator	Name	Example
&	AND	x & y
|	OR	x | y
^	XOR	x ^ y
~	NOT	~x
«	Zero fill left shift	x « y
»	Signed right shift	x » y

Operator Precedence

• 앞서 썼던 연산자 포함 연산자 우선순위.
  나머지는 앞으로 오며가며 볼꺼니까.
• 위쪽으로 우선순위가 높고
  같은 상자안에서는 순서상관없이 같음.
• 구문이 명시적이지 않으면
  연산자는 binary

Operator	Description
(expressions…),[expressions…],  {key: value…}, {expressions…}	Binding, parenthesized expression, list display, dictionary display, set display
x[index], x[index:index],  x(arguments…), x.attribute	Subscription, slicing, call, attribute reference
await x	Await expression
**	Exponentiation
+x, -x, ~x	Positive, negative, bitwise NOT
*, @, /, //, %	Multiplication, matrix multiplication, division, floor division, remainder
+, -	Addition and subtraction
«, »	Shifts
&	Bitwise AND
^	Bitwise XOR
|	Bitwise OR
in, not in, is, is not,  <, <=, >, >=, !=, ==	Comparisons, membership , identity
not x	Boolean NOT
and	Boolean AND
or	Boolean OR
if – else	Conditional expression
lambda	Lambda expression
:=	Assignment expression