BASIC OPERATIONS

How does % work?

Another way to say it is, "X divided by Y with J remaining." For example, "100 divided by 16 with 4 remaining." The result of % is the J part, or the remaining part.

Arithmetic Operators

Assume variable a holds 10 and variable b holds 20, then + Addition Adds values on either side of the operator. a + b = 30 - Subtraction Subtracts right hand operand from left hand operand. a - b = -10 * Multiplication Multiplies values on either side of the operator a * b = 200 / Division Divides left hand operand by right hand operand b / a = 2 % Modulus Divides left hand operand by right hand operand and returns remainder b % a = 0 ** Exponent Performs exponential (power) calculation on operators a**b =10 to the power 20 // Floor Division - The division of operands where the result is the quotient in which the digits after the decimal point are removed. But if one of the operands is negative, the result is floored, i.e., rounded away from zero (towards negative infinity) 9//2 = 4 and 9.0//2.0 = 4.0, -11//3 = -4, -11.0//3 = -4.0

Assignment Operators

Assume variable a holds 10 and variable b holds 20, then − = Assigns values from right side operands to left side operand c = a + b assigns value of a + b into c += Add AND It adds right operand to the left operand and assign the result to left operand c += a is equivalent to c = c + a -= Subtract AND It subtracts right operand from the left operand and assign the result to left operand c -= a is equivalent to c = c - a *= Multiply AND It multiplies right operand with the left operand and assign the result to left operand c *= a is equivalent to c = c * a /= Divide AND It divides left operand with the right operand and assign the result to left operand c /= a is equivalent to c = c / ac /= a is equivalent to c = c / a %= Modulus AND It takes modulus using two operands and assign the result to left operand c %= a is equivalent to c = c % a **= Exponent AND Performs exponential (power) calculation on operators and assign value to the left operand c **= a is equivalent to c = c ** a //= Floor Division It performs floor division on operators and assign value to the left operand c //= a is equivalent to c = c // a

Bitwise Operators

Bitwise operator works on bits and performs bit by bit operation. Assume if a = 60; and b = 13; Now in binary format they will be as follows − a = 0011 1100 b = 0000 1101 ----------------- a&b = 0000 1100 a|b = 0011 1101 a^b = 0011 0001 ~a = 1100 0011 There are following Bitwise operators supported by Python language & Binary AND Operator copies a bit to the result if it exists in both operands (a & b) (means 0000 1100) | Binary OR It copies a bit if it exists in either operand. (a | b) = 61 (means 0011 1101) ^ Binary XOR It copies the bit if it is set in one operand but not both. (a ^ b) = 49 (means 0011 0001) ~ Binary Ones Complement It is unary and has the effect of 'flipping' bits. (~a ) = -61 (means 1100 0011 in 2's complement form due to a signed binary number. << Binary Left Shift The left operands value is moved left by the number of bits specified by the right operand. a << 2 = 240 (means 1111 0000) >> Binary Right Shift The left operands value is moved right by the number of bits specified by the right operand. a >> 2 = 15 (means 0000 1111)

Python Identity Operators

Identity operators compare the memory locations of two objects. There are two Identity operators explained below − is Evaluates to true if the variables on either side of the operator point to the same object and false otherwise. x is y, here is results in 1 if id(x) equals id(y). is not Evaluates to false if the variables on either side of the operator point to the same object and true otherwise. x is not y, here is not results in 1 if id(x) is not equal to id(y).

PEMDAS

In the United States we use an acronym called PEMDAS which stands for Parentheses Exponents Multiplication Division Addition Subtraction. That's the order Python follows as well The mistake people make with PEMDAS is to think this is a strict order, as in "Do P, then E, then M, then D, then A, then S. The actual order is you do the multiplication and division (M&D) in one step, from left to right, then you do the addition and subtraction in one step from left to right. So, you could rewrite PEMDAS as PE(M&D)(A&S).

Why is the % character a "modulus" and not a "percent"?

Mostly that's just how the designers chose to use that symbol. In normal writing you are correct to read it as a "percent." In programming this calculation is typically done with simple division and the / operator. The % modulus is a different operation that just happens to use the % symbol.

Operator

Operators are the constructs which can manipulate the value of operands. Consider the expression 4 + 5 = 9. Here, 4 and 5 are called operands and + is called operator.

Types of Operator

Python language supports the following types of operators. Arithmetic Operators Comparison (Relational) Operators Assignment Operators Logical Operators Bitwise Operators Membership Operators Identity Operators

Python Operators Precedence

The following table lists all operators from highest precedence to lowest. 1 ** Exponentiation (raise to the power) 2 ~ + - Complement, unary plus and minus (method names for the last two are +@ and -@) 3 * / % // Multiply, divide, modulo and floor division 4 + - Addition and subtraction 5 >> << Right and left bitwise shift 6 & Bitwise 'AND' 7 ^ | Bitwise exclusive `OR' and regular `OR' 8 <= < > >= Comparison operators 9 <> == != Equality operators 10 = %= /= //= -= += *= **= Assignment operators 11 is is not Identity operators 12 in not in Membership operators 13 not or and Logical operators

Logical Operators

There are following logical operators supported by Python language. Assume variable a holds 10 and variable b holds 20 then and Logical AND If both the operands are true then condition becomes true. (a and b) is true. or Logical OR If any of the two operands are non-zero then condition becomes true. (a or b) is true. not Logical NOT Used to reverse the logical state of its operand. Not (a and b) is false.

Comparison Operators

These operators compare the values on either sides of them and decide the relation among them. They are also called Relational operators. Assume variable a holds 10 and variable b holds 20, then − == If the values of two operands are equal, then the condition becomes true. (a == b) is not true. != If values of two operands are not equal, then condition becomes true. (a != b) is true. <> If values of two operands are not equal, then condition becomes true. (a <> b) is true. This is similar to != operator. > If the value of left operand is greater than the value of right operand, then condition becomes true. (a > b) is not true. < If the value of left operand is less than the value of right operand, then condition becomes true. (a < b) is true. >= If the value of left operand is greater than or equal to the value of right operand, then condition becomes true. (a >= b) is not true. <= If the value of left operand is less than or equal to the value of right operand, then condition becomes true. (a <= b) is true.

What is the order of operations?

What is the order of operations? In the United States we use an acronym called PEMDAS which stands for Parentheses Exponents Multiplication Division Addition Subtraction. That's the order Python follows as well. The mistake people make with PEMDAS is to think this is a strict order, as in "Do P, then E, then M, then D, then A, then S. " The actual order is you do the multiplication and division (M&D) in one step, from left to right, then you do the addition and subtraction in one step from left to right. So, you could rewrite PEMDAS as PE(M&D)(A&S).