Learn Python

Variables in Python

Variables are the character(s) used to store a value to be used further in the program. For example, when you want to store roll number of a student in the program then we use some variables to store roll number data:

Roll_no = 35

In the above statement we use an identifier(Roll_no) to store roll number of a student of integer type. Then we can call Roll_no a numeric variable.

Em_name = "Ricc"

Then we can call Em_name a string variable.

IMPORTANT:

In Python, you cannot use integer, float, complex number, expression as a variable as it will raise an error. You can only use characters, or identifiers to store any value.

For example:

36=Id

25=x

2a/c=20

In Python, you can use multiple assignments. #that's nice

For example:

A,B,C=5,10,15

x=y=z=50

Dynamic Typing

A variable who is used to store a value of one type, can be used again to store a value of different type. Python uses Dynamic Typing.

For example:

x=5
print(x)
x=10.5
print(x)
x="PyCodeWiz"
print(x)

Then the output will be as follows:

510.5
PyCodeWiz

Types Of Literals

(i) Numeric Literal : In Python , you can use integers, float or complex numbers as numeric literals.

Integers are the whole numbers without decimal having either positive(+) or negative(-) sign. A number without sign considered as positive.

For example: +49, -345, 89, -99,etc.

Floats are real numbers and always contain decimal point or fractional part.

For example: 5.35, -50.1, 99.99, etc.

Complex numbers are the numbers of form a+ib, where a and b are int or float type, i represents the imaginary number. a is real part of complex number and b is the imaginary part of the complex number.

(ii) String Literals : In Python, character(s) which are enclosed in quotes(single quote(') or double quote(") ).

(iii) Boolean Literals : In Python, Boolean literals are used to store either True or False. True are False are the only boolean literal value.

(iv) None Literal(Special Literal) : Python has one special literal, which is None Literal. The None Literal is used to represent or points absence of value. None means nothing.

Types Of Operators

(i) Arithmetic Operators:

+ Addition

- Subtraction

* Multiplication

/ Division

** Exponent

// Floor Division

% Modulus

(ii) Logical Operators:

or Logical OR

and Logical AND

(iii) Membership Operators:

in whether the character in sequence

not in whether the character not in sequence

(iv) Relational Operators:

< Less than

<= Less than or equal to

> Greater than

>= Greater than or equal to

== Equal to

!= Not equal to

(v) Bitwise Operators:

| Bitwise OR

& Bitwise AND

^ Bitwise XOR

(vi) Assignment Operators:

= Assignment

+= Assign sum

-= Assign difference

*= Assign Product

/= Assign quotient

%= Assign remainder

**= Assign exponent

//= Assign floor division

(vii) Identity Operators:

is is identity same?

is not is identity not same?

If you have any queries, feel free to ask.