Python Lists in Class XI Module-4 by Mrs. Sujata Pradhan
PYTHON
LIST
CLASS XI
(MODULE-4)
BY
Mrs.
SUJATA
PRADHAN,
PGT(SS),
Computer
Science,
AECS,ANUPURAM
SUMMARY
OF
PYTHON
LIST
List structure
and
characteristics
Mutability
Basic
List
operations
Positive
&
Negative
Indexing
List
slicing
Concatenation
&
Repetition
Membership
Operation
List
traversal
List
updation
List
comparison
List
methods
append()
extend()
insert()
index()
sort()
count()
reverse()
pop()
remove()
clear()
Insert an
element
in a
list:
The
list.insert(i,x)
method
The
list.append(x)
method
Concatenate
two
lists:
+
operator
list.extend(iterable)
removing
elements
from
a
list
There
are
three
ways
of
removing
elements
from
a
list:
•
Using the
del
keyword
–
delete one
or multiple
items
of a
list using
the
del
keyword
,
•
Using the
list.remove(x)
method
–
The
list.remove(x)
method deletes
the
first
matching
element
from
the
list
.
•
Using the
list.pop([x])
method
–
The
list.pop([x])
method
removes
the
item at
the
given
index,
and
returns
it. If the
index
is not
provided,
the
list.pop()
method
removes
and
returns
the
last
item
of
the
list.
Python
Linear
search
on
list
What
is a Linear
Search?
A
linear
search
is also known as a sequential
search.
It is a
method
of finding an
element
within a
list
by
checking each element of the
list
sequentially
until
a
match
is
found.
Procedure
:
•
Start
search
from
the
leftmost
element of
list.
•
compare
searched element
,say
X
with
each
element
of the
list
one
by
one.
•
If X
matches
with
any
element of
the
list,
search
is
successful.
•
If it doesn't
match
with
any
of elements,
it is an
unsuccessful
search.
List
Creation
A
list
is
an
ordered
and
mutable
Python
container
.It is
one of
the
most common data structures
in
Python
.
To
create
a
list
,
the
elements
are
placed inside
square
brackets
(
[]
)
and
separated by
commas.
Generally
we
create
a
new list
using
three
steps.
•
Create
an
empty
list.
•
Loop
through
the
list.
•
Append the
elements to
the
new
list.
L =
[]
found
=
False
n =
int(input("Enter size
of
list"))
for
i in
range(n):
num =
int(input("Enter a number:
"))
L.a
pp
e
n
d
(n
u
m)
print(“List:”,L)
X =
int(input(“Enter
a number
to
search:"))
for
i in
range(len(L)):
if L[i]
==X:
found
=
True
print(X ,
“found
at
position“,
i+1)
b
r
e
a
k
else:
print(“Unsuccessful
search”)
OUTPUT
Enter size
of
list4
Enter
a
number:
10
Enter
a
number:
25
Enter
a
number:
5
Enter
a
numbers:
30
List:
[10,25,5,30]
Enter
a
number
to
search:
5
5
found
at
position
3
Program for Linear Search
find the
largest
number in
a
list
list1=[]
n=int(input("Enter number of
elements:"))
for
i
in
range(1,n+1):
b=int(input("Enter element:"))list1.append(b)
m
a
x
=
li
s
t1[0]
for
a
in
list1:
if
a
>
max:
max
=
a
print(“Largest
element
is:”,
max)
OUTPUT:
Enter
number
of
elements:5
Enter
element:2
Enter
element:5
Enter
element:3
Enter
element:7
Enter
element:6
Largest element
is:
7
#Using
sort()
a=[]
n=int(input("Enter number
of elements:"))
for
i
in
range(1,n+1):
b=int(input("Enter element:"))
a.append(b)
a.sort()
print("Largest element is:
",a[n-1])
working
with multi dimensional
list
List
=
[“Hello", “Python",
“World"]
print("Accessing element from
the
list")
print(List[0])
print(List[2])
List
=
[[‘Hello', ‘Python'] ,
[‘World']]
# accessing an element
from
a Multi-Dimensional
List
print("Accessing element
from
a
Multi-Dimensional
list")
print(List[0][1])
print(List[1][0])
Output:
Accessing element
from
the
list
Hello
Python
Accessing element
from
a Multi-Dimensional
list
Python
World
Program
to
add
two
matrices using
nested
loop
X
=
[[12,7,3],
[4
,5,6],
[7
,8,9]]
Y
=
[[5
,
8
,
1],
[6
,
7
,
3],
[4,5
,
9]]
result
=[[0,0,0],
[0,0,0],
[0,0,0]]
for
i
in
range(len(X)):
for
j
in
range(len(X[0])):
result[i][j] = X[i][j] +
Y[i][j]
for
r
in
result:
print(r)
Output
[17, 15,
4]
[10, 12,
9]
[11, 13,
18]
N
ested
loops
are used
to
iterate
through each
row
and
each
column.
program
to
remove duplicate
elements
List1
=
[]
n =
int(input("Enter the number of
elements
in
the
list:"))
for
i
in
range(0,n):
list1.a
p
p
e
n
d(
i
n
p
ut
(
"E
n
t
er the e
l
em
e
n
t:"))
print(“List1=“, list1)
#
Declare
an empty
list that
will
store
unique
values
list2
=
[]
for
i
in
list1:
if
i
not
in
list2:
li
s
t2.a
p
pe
n
d
(
i)
(“List2=”,list2)
Output:
Enter
the
number
of
elements
in the
list:4
Enter
the
element:25
Enter
the
element:46
Enter
the
element:25
List1=[25,46,25]
List2=[25,46]
Thank
You
Exploring list structures, characteristics, and operations in Python. Covering topics such as mutability, basic list operations, indexing, slicing, concatenation, repetition, traversal, updation, and comparison. Detailed explanations on list methods like append, extend, insert, index, sort, count, reverse, pop, remove, and clear. Methods for inserting elements, concatenating lists, and various ways of removing elements. Understanding linear search in Python lists with a step-by-step procedure. Creation of lists in Python and a sample program for linear search along with output demonstration.
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Presentation Transcript
PYTHONLIST CLASS XI (MODULE-4) BY Mrs. SUJATAPRADHAN, PGT(SS), Computer Science, AECS,ANUPURAM
SUMMARY OF PYTHON LIST List structure and characteristics Mutability Basic List operations Positive & NegativeIndexing List slicing Concatenation &Repetition Membership Operation List traversal List updation List comparison
List methods append() extend() insert() index() sort() count() reverse() pop() remove() clear() Insert an element in a list: The list.insert(i,x) method The list.append(x) method Concatenate two lists: +operator list.extend(iterable)
removing elements from a list There are three ways of removing elements from a list: Using the del keyword delete one or multiple items of a list using the del keyword, Using the list.remove(x)method The list.remove(x) method deletes the first matching element from the list. Using the list.pop([x])method The list.pop([x]) method removes the item at the given index, and returns it. If the index is not provided, the list.pop() method removes and returns the last item of the list.
Python Linear search on list What is a Linear Search? A linear search is also known as a sequential search. It is a method of finding an element within a list by checking each element of the list sequentially until a match is found. Procedure: Start search from the leftmost element of list. compare searched element ,say X with each element of the list one by one. If X matches with any element of the list, search is successful. If it doesn't match with any of elements, it is an unsuccessfulsearch.
List Creation A list is an ordered and mutable Python container.It is one of the most common data structures in Python.To create a list, the elements are placed inside square brackets ([]) and separated by commas. Generally we create a new list using three steps. Create an empty list. Loop through the list. Append the elements to the new list.
Program for Linear Search L = [] found = False n = int(input("Enter size of list")) for i in range(n): num = int(input("Enter a number: ")) L.append(num) print( List: ,L) X = int(input( Enter a number to search:")) for i in range(len(L)): if L[i] ==X: found = True print(X , found at position , i+1) break else: print( Unsuccessfulsearch ) OUTPUT Enter size of list4 Enter a number: 10 Enter a number: 25 Enter a number: 5 Enter a numbers: 30 List: [10,25,5,30] Enter a number to search: 5 5 found at position 3
find the largest number in alist list1=[] n=int(input("Enter number of elements:")) for i in range(1,n+1): b=int(input("Enter element:")) list1.append(b) max=list1[0] for a in list1: if a > max: max =a print( Largest element is: , max) OUTPUT: Enter number of elements:5 Enter element:2 Enter element:5 Enter element:3 Enter element:7 Enter element:6 Largest element is:7 #Using sort() a=[] n=int(input("Enter number of elements:")) for i in range(1,n+1): b=int(input("Enter element:")) a.append(b) a.sort() print("Largest element is:",a[n-1])
working with multi dimensionallist List = [ Hello", Python", World"] print("Accessing element from the list") print(List[0]) print(List[2]) List = [[ Hello', Python'] ,[ World']] # accessing an element from a Multi-Dimensional List print("Accessing element from a Multi-Dimensionallist") print(List[0][1]) print(List[1][0]) Output: Accessing element from thelist Hello Python Accessing element from a Multi-Dimensionallist Python World
Program to add two matrices using nested loop X = [[12,7,3], [4,5,6], [7,8,9]] [[5,8,1], [6,7,3], [4,5,9]] Nested loops are used to iterate through each row and eachcolumn. Y = Output [17, 15,4] [10, 12,9] [11, 13, 18] result=[[0,0,0], [0,0,0], [0,0,0]] for i in range(len(X)): for j in range(len(X[0])): result[i][j] = X[i][j] + Y[i][j] for r in result: print(r)
program to remove duplicate elements List1 = [] n = int(input("Enter the number of elements in the list:")) for i in range(0,n): list1.append(input("Enter the element:")) print( List1= , list1) # Declare an empty list that will store unique values list2 = [] for i in list1: if i not in list2: list2.append(i) print( List2= ,list2) Output: Enter the number of elements in the list:4 Enter the element:25 Enter the element:46 Enter the element:25 List1=[25,46,25] List2=[25,46]
