Operators and their usage

August 1, 2010 at 9:57 pm (Python)

Operator Name Explanation Examples
+ Plus Adds the two objects 3 + 5 gives 8. ‘a’+’b’ gives ‘ab’.
Minus Either gives a negative number or gives the subtraction of one number from the other -5.2 gives a negative number. 50 – 24 gives 26.
* Multiply Gives the multiplication of the two numbers or returns the string repeated that many times. 2 * 3 gives 6. ‘la’ * 3 gives ‘lalala’.
** Power Returns x to the power of y 3 ** 4 gives 81 (i.e. 3
of 3* 3 * 3 * 3)
/ Divide Divide x by y 4/3 gives 1 (division of integers gives an integer).4.0/3 or 4/3.0 gives 1.3333333333333333
// Floor Division Returns the floor of the quotient 4 // 3.0 gives 1.0
% Modulo Returns the remainder of the division 8%3 gives 2. 25.5%2.25 gives 1.5
<< Left Shift Shifts the bits of the number to the left by the number of bits specified. (Each number is represented in memory by bits or binary digits i.e. 0 and1) 2 << 2 gives 8. – 2 is represented by 10 in bits. Left shifting by 2 bits gives 1000 which represents the decimal 8.
>> Right Shift Shifts the bits of the number to the right by
the number of bits specified.
11 >> 1 gives 5 – 11 is represented in bits by 1011 which when right shifted by 1 bit gives 101 which is nothing but decimal 5.
& Bitwise AND Bitwise AND of the 5 numbers & 3 gives 1.
| Bit-wise OR Bitwise OR of the numbers 5 | 3 gives 7
^ Bit-wise XOR Bit-wise XOR 5 ^ 3 gives 6
~ Bit-wise invert The bit-wise inversion of x is -(x+1) ~5 gives -6.
< Less Than Returns whether x is less than y. All comparison operators return 1 for true and 0 for false. This is equivalent to the special variables True and False respectively.Note the capitalization of these variables’ names. 5 < 3 gives 0 (i.e. False) and 3 < 5 gives 1 (i.e. True). Comparisons can be chained arbitrarily: 3 < 5 < 7 gives True.
> Greater Than Returns whether x is greater than y > Greater Than Returns whether x is 5 < 3 returns True. If greater than y both operands are numbers, they are first converted to a common type. Otherwise, it always returns False.
<= Less Than or Equal To Returns whether x is less than or equal to y x = 3; y = 6; x <= y returns True.
>= Greater Than or Equal To Returns whether x is greater than or equal to y x = 4; y = 3; x >= 3 returns True.
== Equal To Compares if the objects are equal x = 2; y = 2; x== y returns True. x=
‘str’; y =’stR’; x == y returns False. x =’str’;y=’str’; x == y returns True.
!= Not Equal To Compares if the objects are not equal x = 2; y = 3; x!= y returns True.
not Boolean NOT If x is True, it returns False. If x is False, it returns True. x = True; not y returns False.
and Boolean AND x and y returns False if x is False, else it returns evaluation of y x = False; y =True; x and y returns False since x is False. In this case, Python will not evaluate y since it knows that the value of the expression will has to be false (since x is False). This is called short-circuit evaluation.
or Boolean OR If x is True, it returns True, else it returns evaluation of y x = True; y =False; x or y returns True. Short-circuit evaluation applies here as well.
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