Python Cheat Sheet
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 the operator.
Python language supp orts the following types of operators-
Assume variable a holds the value 10 and variable b holds the value 21, then-
Operators and their description:-
Adds values on either side of the operator.
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a + b = 31Subtracts right hand operand from left hand operand.
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a - b = -11Multiplies values on either side of the operator
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a * b = 210left hand operand by right hand operand
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b / a = 2.1left hand operand by right hand operand and returns remainder
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b % a = 1Performs exponential (power) calculation on operators
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a ** b = 10 to the power 20Floor Division - The division of operands where the result is the quotient in which the digits after the decimal point are removed.
example:-
9//2 = 4 and 9.0//2.0 = 4.0These operators compare the values on either side of them and decide the relation among them. They are also called Relational operators.
Assume variable a holds the value 10 and variable b holds the value 20, then-
If the values of two operands are equal, then the condition becomes true.
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(a == b) is not true.If values of two operands are not equal, then condition becomes true.
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(a!=b) is true.If the value of left operand is greater than the value of right operand, then condition becomes true.
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(a > b) is not true.If the value of left operand is less than the value of right operand, then condition becomes true.
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(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.
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(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.
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(a <= b) is true.Assume variable a holds 10 and variable b holds 20, then-
Assigns values from right side operands to left side operand
example-
c = a + b assigns value of a + b into cIt adds right operand to the left operand and assign the result to left operand
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c+= a is equivalent to c = c + aIt subtracts right operand from the left operand and assign the result to left operand
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c-= a is equivalent to c = c - aIt multiplies right operand with the left operand and assign the result to left operand
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c*= a is equivalent to c = c * aIt divides left operand with the right operand and assign the result to left operand
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c/= a is equivalent to c = c / a, c /= a is equivalent to c = c / aIt takes modulus using two operands and assign the result to left operand
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c%= a is equivalent to c = c % aPerforms exponential (power) calculation on operators and assign value to the left operand
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c**= a is equivalent to c = c ** aIt performs floor division on operators and assign value to the left operand
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c//= a is equivalent to c = c // aBitwise 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
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a&b = 0000 1100
a|b = 0011 1101
a^b = 0011 0001
~a = 1100 0011
Pyhton's built-in function bin() can be used to obtain binary representation of an integer number.
The following Bitwise operators are supported by Python language-
Operator copies a bit to the result, if it exists in both operands
example:-
(a & b) (means 0000 1100)
It copies a bit, if it exists in either operand.
example:-
(a | b) (means 0011 1101It copies the bit, if it is set in one operand but not both.
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(a ^ b) = 49 (means 0011 0001)It is unary and has the effect of 'flipping' bits.
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(~a ) = -61 (means 1100 0011 in 2's complement form due to a signed binary number.The left operand’s value is moved left by the number of bits specified by the right operand.
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a << = 240 (means 1111 0000)The left operand’s value is moved right by the number of bits specified by the right operand.
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a >> = 15 (means 0000 1111)The following logical operators are supported by Python language. Assume variable a holds True and variable b holds False then-
If both the operands are true then condition becomes true.
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(a and b) is False.If any of the two operands are non-zero then condition becomes true.
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(a or b) is True.Used to reverse the logical state of its operand.
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Not(a and b) is True.Python’s membership operators test for membership in a sequence, such as strings, lists, or tuples. There are two membership operators as explained below-
Evaluates to true, if it finds a variable in the specified sequence and false otherwise.
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x in y, here in results in a 1 if x is a member of sequence y.Evaluates to true, if it does not find a variable in the specified sequence and false otherwise.
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x not in y, here not in results in a 1 if x is not a member of sequence YIdentity operators compare the memory locations of two objects. There are two Identity operators as explained below:
Evaluates to true if the variables on either side of the operator point to the same object and false otherwise.
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x is y, here is results in 1 if id(x) equals id(y).Evaluates to false if the variables on either side of the operator point to the same object and true otherwise.
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x is not y, here is not results in 1 if id(x) is not equal to id(y)The following table lists all the operators from highest precedence to the lowest.
Exponentiation (raise to the power)Complement, unary plus and minus (method names for the last two are +@ and -@)Multiply, divide, modulo and floor divisionAddition and subtractionRight and left bitwise shiftBitwise 'AND'Bitwise exclusive `OR' and regular `OR'Comparison operatorsEquality operatorsAssignment operatorsIdentity operatorsMembership operatorsLogical operators