Let's Python with VIJIN (Part-4)

These are keywords which determine the type of data stored in a variable. Following table shows data types used in python:

Immutable data types: They are those that can never change their value in place.

Immutable types are:

·       integer

·       floating point numbers

·       booleans

·       strings

·       types

Let us now try to execute few statements in interactive mode to determine the data type of the variable using built-in function type().

String

·       String is a group of characters.

·       These characters may be alphabets, digits or special characters including spaces.

·       String values are enclosed either in single quotation marks (e.g., ‘Hello’) or in double

quotation marks (e.g., “Hello”).

·       The quotes are not a part of the string, they are used to mark the beginning and end of

the string for the interpreter.

o   >>> str1 = 'Hello Friend'

o   >>> str2 = "452"

We cannot perform numerical operations on strings, even when the string contains a numeric value, as in str2.

o   type('Hi')

<class 'str'>

Mutable data types:

They are their value can be changed in place

Immutable types are:

·       Lists

·       Dictionaries

·       Sets

List:

·       Lists are used to store multiple items in a single variable.

·       List is a mutable datatype.

·       Example:

>>>list1=[1,2,3,4,5]

>>>type(list1)

<class ‘list’>

>>>list2=[‘a’, ’e’, ’i’, ‘o’, ‘u’]

>>>list3=[‘Krupa’, 102, 79.5] 

Tuple:

·       Tuples are used to store multiple items in a single variable.

·       Tuple is an immutable datatype.

·       Example:

>>>tup1=(1,2,3,4,5)

>>>type(tup1e1)

<class ‘’tuple>

>>>tup2=(‘a’, ’e’, ’i’, ‘o’, ‘u’)

>>>tup3=(‘Krupa’, 102, 79.5) 

Set:

·       Sets are used to store multiple items in a single variable.

·       Set is a mutable datatype.

·       Duplicate elements are not allowed in a set.

·       Example:

>>>set1={1,2,3,4}    

>>>set2={‘a’, ’e’, ’i’, ‘o’, ‘u’}

>>>type(set1)

<class ‘set’>

>>>set3={‘Krupa’, 102, 79.5}

Dictionary

·       Dictionaries are used to store data value in key:value pairs.

·       Dictionary is a mutable datatype.

·       Example:

>>>dict1={‘a’:1, ‘e’:2, ‘i’:3,’o’:4,’u’:5}

>>>type(dict1)

<class 'dict'>

>>>dict1[‘e’]

2

>>>student={

“regno”:123,

“name”: “ram”,

“class” : “PCMC”

      }   

None

·       None is a special data type with a single value.

·       It is used to signify the absence of value in a situation.

·       None supports no special operations, and it is neither same as False nor 0 (zero).

>>> myVar = None

>>> print(type(myVar))

<class ‘None Type’>

>>> print(myVar)

None