The Number data type is used to hold the numeric values. Python supports following numerical data types –
| Type | Format | Description | ||||
|---|---|---|---|---|---|---|
| int | a = 10 | Signed Integer | ||||
| long | a = 345L | (L) Long integers, they can also be represented in octal and hexadecimal | ||||
| float | a = 45.67 | (.) Floating point real values | ||||
| complex | a = 3.14J | (J) Contains integer in the range 0 to 255. |
In Python programming, an operator is a special symbol that is used to carry out some specific operation on its operand. In Python, we have rich set of built in operators to carry out different type of operations. There are operators for assignment, arithmetic operations, logical operations and comparison operations etc. Python operators can be used with many types of variables or constants, but some of the operators are restricted to work on specific data types. Most operators are binary, meaning they take two operands, but a few are unary and only take one operand.
Python supports the following types of operators –
Arithmetic Operators are used to perform arithmetic operations like addition, subtraction, multiplication, division, %modulus, exponent, etc. For example assume a=5 and b=10, then –
| Symbol | Name | Description | Example |
|---|---|---|---|
| + | Addition | It perform the addition of both the operands. | a + b = 15 |
| – | Subtraction | It subtract right operand from the left | a – b = -5 |
| * | Multiplication | It performs the multiplication of the given operands | a * b = 50 |
| / | Division | It performs the division of the left operand by the right operand | b / a = 2 |
| % | Modulus | It returns the remainder of the division of left operand by the right | b % a = 0(remainder of b/a) |
| // | Floor Division | It performs the division of operands where it returns the quotient in which the digits after the decimal point are removed. | 15 // 4 = 3, 19//5=3 |
| ** | Exponent | Left operand raised to the power of right | a**b = (a to the power b), 3**4=81 |
Assignment operators are used to assign value to a variable, you can assign a variable value or the result of an arithmetical expression.
| Symbol | Name | Description | Example |
|---|---|---|---|
| = | Assignment | Used to assigns a value to variable(s). | c = a + b assigns value of a + b into c |
| += | Add and assign | It is shorthand to add right operand to the left operand and assign the result to left operand | c += a is equivalent to c = c + a |
| -= | Subtract and assign | It is shorthand to subtracts right operand from the left operand and assign the result to left operand | c -= a is equivalent to c = c – a |
| *= | Multiply and assign | It is shorthand to multiply right operand with the left operand and assign the result to left operand | c *= a is equivalent to c = c * a |
| /= | Divide and assign | It is shorthand to divide 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 assign | It is shorthand to take modulus using two operands and assign the result to left operand | c %= a is equivalent to c = c % a |
| **= | Exponent and assign | It is shorthand to perform exponential (power) calculation on operators and assign value to the left operand | c **= a is equivalent to c = c ** a |
| //= | Floor Division and assign | It is shorthand to performs floor division on operators and assign value to the left operand | c //= a is equivalent to c = c // a |
Comparison Operators are used evaluate a comparison between two operands. The result of a comparison operation is a Boolean value that can only be true or false. Comparison Operators are also referred as relational operators.
Here is full list of Relational operators available in Python Programming Language –
| Operator | Meaning | Example | Description |
|---|---|---|---|
| == | Equal to | a == b | 1 if a equal to b; 0 otherwise |
| != | Not equal to | a != b | 1 if a not equal to b; 0 otherwise |
| > | greater than | a > b | 1 if a > b; 0 otherwise |
| < | less than | a < b | 1 if a < b; 0 otherwise |
| >= | greater than or equal to | a >= b | 1 if a >= b; 0 otherwise |
| <= | less than or equal to | a <= b | 1 if a <= b; 0 otherwise |
Logical operators are used to combine expressions with conditional statements using logical (AND,OR,NOT) operators, which results in true or false.
There are 3 logical operators available in Python Programming Language
| Operator | Meaning | Example | Description |
|---|---|---|---|
| and | Logical AND | a and b | Logical AND of a and b |
| or | Logical OR | a or b | Logical OR of a and b |
| not | Logical NOT | not a | Logical NOT of a |
Identity Operators are used to compare the memory location of two objects.
There are two identify operators available in Python (is, is not).
| Operator | Name | Meaning | Example |
|---|---|---|---|
| is | Name | It returns True if both the operands are identical and refers to the same object | x is True |
| is not | Name | It returns True if both the operands are not identical or they refer to different objects | x is not True |
Bitwise operator are used to perform bit level operation over its operand.
Let A = 60; and B = 13;
Binary equivalent
A = 0011 1100
B = 0000 1101
| Operator | Meaning | Example | Description |
|---|---|---|---|
| & | Binary AND | (A & B) | It returns 12 which is 0000 1100 |
| | | Binary OR | (A | B) | It returns 12 which is 0000 1100 |
| ^ | Binary XOR | (A ^ B) | It returns 49 which is 0011 0001 |
| ~ | Ones Complement | (~A ) | It returns -60 which is 1100 0011 |
| << | shift left | A << 2 | It returns 240 which is 1111 0000 |
| >> | shift right | A >> 2 | It returns 15 which is 0000 1111 |
Membership operators are used to test membership in a sequence, such as strings, lists, or tuples.
There are two membership operators available in python.
| Operator | Name | Meaning | Example |
|---|---|---|---|
| in | Name | It returns True if value/variable is found in the given sequence, FALSE otherwise | 5 in x |
| not in | Name | It returns True if value/variable is not found in the given sequence, FALSE otherwise | 5 not in x |
Highest precedence at top, lowest at bottom.
Operators in the same box evaluate left to right.
| Operators | Meaning |
|---|---|
| () | Parentheses |
| ** | Exponent |
| +x, -x, ~x | Unary plus, Unary minus, Bitwise NOT |
| *, /, //, % | Multiplication, Division, Floor division, Modulus |
| +, – | Addition, Subtraction |
| <<, >> | Bitwise shift operators |
| & | Bitwise AND |
| ^ | Bitwise XOR |
| | | Bitwise OR |
| ==, !=, >, >=, <, <=, is, is not, in, not in | Comparisions, Identity, Membership operators |
| not | Logical NOT |
| and | Logical AND |
| or | Logical OR |
An identifiers is a name given to program elements such as variables , array, class and functions etc. An identifier is a sequence of letters, digits, and underscores, the first character of which can not be a digit. Following rules must be kept in mind while naming an identifier.
Note :- Python is a case-sensitive programming language, which means “Abc” and “abc” are not the same.
Python keywords are set words that cannot be used as an identifier in program. These words are known as “Reserved Words” or “Keywords”. Python Keywords are standard identifiers and their meaning and purpose is predefined by the compiler.
Below is list of available keywords in Python programming Language.
| and | assert | in |
| del | else | raise |
| from | if | continue |
| not | pass | finally |
| while | yield | is |
| as | break | return |
| elif | except | def |
| global | import | for |
| or | lambda | |
| with | class | try |
| exec |
Note :-We cannot use keywords for declaring Variable Name,For Function Name and for declaring Constant Variable
The “Hello world!” program is a simplest program that will display some text on the screen. The “Hello world!” program is a simple yet complete program for beginners that illustrates the basic syntax of any programming language. The “Hello world!” program gives you a way to test systems and programming environment.
This tutorial will guide you through writing a basic “Hello, World” program in Python.
Before starting with this tutorial we assume that you already have Python installed (If you do not have Python installed then install it before you get started) as well as a local programming environment set up on your computer.
Step 1:- Create a file called “hello_world.py” using a text editor program of your choice. The .py file extension is used to specify Python language file.
Step 2:- Let’s open the “hello_world.py” file that we created, and put the following line of code in it and save it.
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print("Hello, World!") |
The print() is a function that tells Python to display or output the content inside the parentheses.
Step 3:- Now, open terminal or command prompt and switch to the folder where our “hello_world.py” file is saved. Run the program by typing the following command –
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python hello_world.py |
Once the program is executed it will print “Hello World!”.
Output:-
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Hello World! |