- 2020-06-01 16:18
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<> Arithmetic operator

In the above , We've talked about Canada , reduce , ride , except , Take surplus , Take mold , Power operation total 7 Seed run . This kind of symbol is called “ operator ”, We talked about 7 All operators belong to “ Arithmetic operator ”.

operator function

+ number + number = Summation ; character string + character string = Merge strings in order before and after

- number - number = Calculate the difference

* number * number = quadrature ; character string * number = String repeated several times

/ number / number = Seeking quotient

% number % number = Take surplus ( Remainder of division )

// number // number = Take mold ( Integral part of quotient )

** number ** number = exponentiation ( Power of the last power of the first number ) a = 5 b = 3 print(a + b) # Output value : 8 print(a - b) # Output value : 2

print(a * b) # Output value : 15 print(a / b) # Output value : 1.6666666666666667 print(a % b) #

Output value : 2 print(a // b) # Output value : 1 print(a ** b) # Output value : 125

Except for arithmetic operators , And assignment operators , Comparison operator , Logical operators , member operator , Identity operator , Bitwise Operators .

<> Assignment Operators

below , Let's first understand that it's the same as arithmetic operators , Assignment operators also related to calculation . This kind of operators can operate at the same time of variable assignment .

operator function

= Assign the content after the equal sign to the variable before the equal sign ; for example ：a=3 Is to 3 Assigned to variable a

+= Add the contents after the equal sign to the variables before the equal sign , for example ：a+=3 Is equivalent to a=a+3

-= Reduce the contents after the equal sign to the variables before the equal sign , for example ：a-=3 Is equivalent to a=a-3

*= Multiply the contents after the equal sign to the variables before the equal sign , for example ：a*=3 Is equivalent to a=a*3

/= Take the contents before the equal sign as divisor , Contents after equal sign as divisor , And assign the result of division to the variable before the equal sign ; for example ：a/=3 Is equivalent to a=a/3

%= Take the contents before the equal sign as divisor , Contents after equal sign as divisor , And assign the remainder result to the variable before the equal sign ; for example ：a%=3 Is equivalent to a=a%3

//= Take the contents before the equal sign as divisor , Contents after equal sign as divisor , And assign the result of modulus to the variable before the equal sign ; for example ：a//=3 Is equivalent to a=a//3

**= Calculating the power of the number of times after the number of equal signs before the number of equal signs , And assign the result to the variable before the equal sign ; for example ：a**=3 Is equivalent to a=a**3 b = 3 a = 5 a += b print(a)

# Output value : 8 a = 5 a -= b print(a) # Output value : 2 a = 5 a *= b print(a) # Output value : 15 a = 5 a

/= b print(a) # Output value : 1.6666666666666667 a = 5 a %= b print(a) # Output value : 2 a = 5 a

//= b print(a) # Output value : 1 a = 5 a **= b print(a) # Output value : 125

<> Comparison operator

The comparison operator is used to compare the size relationship between two variables , The comparison result is Boolean .

operator function

== Judge whether the two variables are the same ; Return if two variables are the same True, Otherwise return False

!= Judge whether the two variables are different ; Return if two variables are different True, Otherwise return False

> x>y Judgment x Is it greater than y; if x greater than y, Then return True, Otherwise return False

< x<y Judgment x Is it less than y; if x less than y, Then return True, Otherwise return False

>= x>=y Judgment x Is greater than or equal to y; if x Greater than or equal to y, Then return True, Otherwise return False

<= x<=y Judgment x Less than or equal to y; if x Less than or equal to y, Then return True, Otherwise return False b = 3 a = 5 print(a == b) #

Output value : False print(a != b) # Output value : True print(a > b) # Output value : True print(a < b) #

Output value : False print(a >= b) # Output value : True print(a <= b) # Output value : False

<> Logical operators

Logical operators are operators used to connect simple logical statements to more complex logical statements , Including or (or), And (and) And non (not).

operator function

or x or y; if x or y One of them is True, The result is True; only x and y All are False The result is False

and x and y; if x and y All of them are True, The result is True; stay x and y One of them is False, The result is False

not not y; if y by True, Then the result is False; if y by False, Then the result is True a = True b = False print(a and b)

# Output value : False print(a or b) # Output value : True print(not b) # Output value : True

<> member operator

member operator (in) Is an operator used to determine whether a sequence contains an element , This sequence can be a string , aggregate , List or tuple, etc . If the sequence contains this element , The returned result is True, Otherwise return False.

a = [1, 2, 3, 4, 5] b = 3 c = 6 print(b in a) # Output value : True print(c in a) # Output value :

False

<> Identity operator

Identity operator (is) It is used to determine whether the variables are from the same object . If it is the same object , Then the result is True, Otherwise, the result is False.

a = 20 b = 10 print(a is b) # Output value : False print(a is not b) # Output value : True

<> Bitwise Operators ( Selected studies )

Bitwise operators evaluate numbers as binary , More efficient operation , But we seldom use it at the beginning of our study .

a = 10 # 0000 1010 b = 5 # 0000 0101 print(a & b) # Output value : 0 print(a | b) # Output value :

15(0000 1111) print(a ^ b) # Output value : 15(0000 1111) print(~a) # Output value : -11(1111 0101)

print(a << 2) # Output value : 40(0010 1000) print(a >> 2) # Output value : 2(0000 0010)

operator function

& Bitwise AND ： If both variables are 1, Then the bit is 1; for example ：1010&0101=0000

/ Bitwise AND ： If two variables in a certain bit only one is 1, Then the bit is 1; for example ：1010&0101=1111

^ Allosteric ： If two variables have different values in a certain bit , Then the bit is 1; for example ：1010&0101=1111

~ Reverse by bit ： Reverses the value of a variable in all bits , Equivalent to calculation -x-1; for example ：~00001010=11110101

<< Left shift ：a<<2 soon a Move two bits to the left , Equivalent to times 4; for example ：00001010<<2=00101000

>> Shift right ：a>>2 soon a Move two bits to the right , Equivalent to divided by 4; for example ：00001010>>2=00000010

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