A list in Python is a collection of values or ordered sequence of values enclosed in square brackets and separated by commas. There are multiple ways to declare and initialize a list, including assigning values like [1,2,3] or using the list() constructor to create a list from other data types like strings. Lists can store heterogeneous data types like integers, strings, floats. Users can input values into lists at runtime using input() and eval() to properly identify the data types.

1. [DECLARATION AND INTIALIZATION OF LIST]
COMPUTER SCIENCE(083)
CLASS: XII
LIST IN PYTHON
PART-1

2. What is List?
How we declare a List?
How we initialize a List?
Different methods of initializing list.

3. WHAT IS LIST:
A list is a collection of values or an ordered sequence of values.
Values in the list can be
Elements of a list enclosed in a square brackets [ ], separated by
commas (,) .
Syntax:
list_name= [value1, value2,……..,valueN]
Example:
No_list = [ 10, 20, 30, 40, 50 ]

4. HOW TO CREATE AND INITIALIZE LIST
Method 1: If list is declare empty.
list1=[ ]
Method 2: Initialize list with value:
If we want to store the numbers in a list.
list2= [10, 20, 30, 40, 50]
If we want to store the words or string in a list.
list3= [“Mango”, “Apple”,”Grapes”,”Oranges”]

5. HOW TO CREATE AND INITIALIZE LIST
If we want to store the characters in a list.
list4= [‘A’,’E’,’I’,’O’,’U’]
If we want to store the mixed information in a list.
list4= [“Kapil”, 13,”Class-IX”, 40]

6. TO DISPLAY THE LIST
Example:
list2= [10, 20, 30, 40, 50]
print(list2)
----------------Output-------------
[10, 20, 30, 40, 50]
Example:
list3= [“Mango”, “Apple”,”Grapes”,”Oranges”]
print(list3)
----------------Output-------------
[‘Mango’, ‘Apple’, ’Grapes’, ’Oranges’]

7. HOW TO CREATE AND INITIALIZE THE
LIST USING LIST() CONSTRUCTOR
Syntax:
list_name=list(sequence or string)
Example:
list1=list(‘Computer’)
print(list1)
----------output----------
[‘C’,’o’,’m’,’p’,’u’,’t’,’e’,’r’]
If we want to store the characters in a list.
list4= list((‘A’,’E’,’I’,’O’,’U’))
---------Output----------
[‘A’, ‘E’,’I’,’O’,’U’]

8. HOW TO CREATE AND INITIALIZE THE
LIST USING LIST() CONSTRUCTOR
Example:
If we want to store the mixed information in a list.
list4= list((“Kapil”, 13,”Class-IX”, 40))
----------------Output-------------
[‘Kapil’, 13,’Class-IX’, 40]
Example: If we want to store the numbers in a list.
List_=list((10, 20, 30, 40, 50))
----------------Output-------------
[10, 20, 30, 40, 50]

9. HOW USER ENTER THE VALUES IN A LIST
AT RUN TIME
Using input() function how we can enter the number inside the list.
If we want to enter number 1,2,3,4,5,6,7,8,9 using keyboard at the
run time
Example:
no=list(input(“Enter the no”))
print(no)
-----------Output-------------
[‘1’,’2’,’3’,’4’,’5’,’6’,’7’,’8’,’9’]
These numbers are store in a character format as these numbers
are display in ‘1’ format.

10. We can use eval( ) method, which identifies the data type and
evaluate them automatically.
Example:
no=eval(input(“Enter the no:”))
print(no)
-------Input-----------
Enter the no: [1,2,3,4,5,6,7,8,9]
-----------Output-------------
[1,2,3,4,5,6,7,8,9]
-------Input-----------
Enter the no: 1,2,3,4,5,6,7,8,9
-----------Output-------------
(1,2,3,4,5,6,7,8,9)
If you enter the number with square
brackets it will create List
If you enter the number without
square brackets it will create tuple