Python operators

PythonOperators are symbols used to perform operations on values and variables.

We can divide it according to the type of operation performed by the operator:

  • Assignment operator
  • Arithmetic Operator
  • Comparison operator
  • Logical Operators
  • Bitwise operator

Plus some interestingiswithin.

Assignment operator

Assignment operators are used to assign values to variables:

age = 8

Or assign the variable value to another variable:

age = 8
anotherVariable = age

Since Python 3.8,:= Walrus operatorUsed to assign values to variables as part of another operation. For example inifOr in the condition part of the loop. talk about it later.

Arithmetic Operator

Python has many arithmetic operators:+,-,*,/(distribution),%(More than),**(Exponentiation) and//(Floor division):

1 + 1 #2
2 - 1 #1
2 * 2 #4
4 / 2 #2
4 % 3 #1
4 ** 2 #16
4 // 2 #2

Note that there is no need for spaces between the operands, but this is helpful for readability.

-It can also be used as a unary negative operator:

print(-4) #-4

+Also used to concatenate string values:

"Roger" + " is a good dog"
#Roger is a good dog

We can combine assignment operators with arithmetic operators:

  • +=
  • -=
  • *=
  • /=
  • %=
  • ..and many more

example:

age = 8
age += 1

Comparison operator

Python defines some comparison operators:

  • ==
  • !=
  • >
  • <
  • >=
  • <=

You can use these operators to get boolean values (TrueorFalse), depending on the result:

a = 1
b = 2

a == b #False a != b #True a > b # False a <= b #True

Boolean operator

Python provides us with the following Boolean operators:

  • not
  • and
  • or

when using itTrueorFalseAttributes, they work like logical AND, OR, and NOT, and are usuallyifConditional expression evaluation:

condition1 = True
condition2 = False

not condition1 #False condition1 and condition2 #False condition1 or condition2 #True

Otherwise, please pay attention to the possible causes of confusion.

orThe value used in the expression returns the value of the first operand, which is not a fake value (False,0,'',[]..). Otherwise, it returns the last operand.

print(0 or 1) ## 1
print(False or 'hey') ## 'hey'
print('hi' or 'hey') ## 'hi'
print([] or False) ## 'False'
print(False or []) ## '[]'

The Python documentation describes it asif x is false, then y, else x.

andThe second parameter is evaluated only when the first parameter is true. Therefore, if the first parameter is false (False,0,'',[]..), the parameter is returned. Otherwise, it will calculate the second parameter:

print(0 and 1) ## 0
print(1 and 0) ## 0
print(False and 'hey') ## False
print('hi' and 'hey') ## 'hey'
print([] and False ) ## []
print(False and [] ) ## False

The Python documentation describes it asif x is false, then x, else y.

Bitwise operator

Some operators are used to deal with bit and binary numbers:

  • &Perform binary AND
  • |Perform binary or
  • ^Perform a binary XOR operation
  • ~Perform a binary NOT operation
  • <<Move left operation
  • >>Move right operation

Those are rarely used and only used in very special circumstances, but they are worth mentioning.

iswithin

isis calledIdentity operator. It is used to compare two objects and returns true if both are the same object. More information about the object will be given later.

inis calledMember operator. Used to determine whether a value is included in a list or another sequence. More information will be provided in the list and other sequences later.


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