# Python Program for Linear Search

Python program for linear search; Through this tutorial, i am going to show you how to implement program for linear search in python using for loop, while loop and recursion function.

A linear search, also known as a sequential search, this method is used to find an element within a list or array. It checks each element of the list one by one / sequentially until a match is found or the whole list has been searched.

In this tutorial, i will write a python programs to perform a linear search with list using for loop, while loop and recursion function.

## Python Program for Linear Search

• Python program for linear search using while loop
• Python program for linear search using for loop
• Linear search in Python using recursion

### python program for linear search using while loop

See the following python program for linear search using while loop; as shown below:

```# python program for linear search using while loop
#define list
lst = []
#take input list size
num = int(input("Enter size of list :- "))
for n in range(num):
#append element in list/array
numbers = int(input("Enter the array of %d element :- " %n))
lst.append(numbers)
#take input number to be find in list
x = int(input("Enter number to search in list :- "))
i = 0
flag = False
while i < len(lst):
if lst[i] == x:
flag = True
break

i = i + 1

if flag == 1:
print('{} was found at index {}.'.format(x, i))
else:
```

After executing the program, the output will be:

```Enter size of list :-  5
Enter the array of 0 element :-  10
Enter the array of 1 element :-  23
Enter the array of 2 element :-  56
Enter the array of 3 element :-  89
Enter the array of 4 element :-  200
Enter number to search in list :-  89
89 was found at index 3.```

### Python program for linear search using For loop

```# python program for linear search using for loop
#define list
lst = []
#take input list size
num = int(input("Enter size of list :- "))
for n in range(num):
#append element in list/array
numbers = int(input("Enter the array of %d element :- " %n))
lst.append(numbers)
#take input number to be find in list
x = int(input("Enter number to search in list :- "))
i = 0
flag = False
for i in range(len(lst)):
if lst[i] == x:
flag = True
break

if flag == 1:
print('{} was found at index {}.'.format(x, i))
else:
```

After executing the program, the output will be:

```Enter size of list :-  6
Enter the array of 0 element :-  25
Enter the array of 1 element :-  50
Enter the array of 2 element :-  100
Enter the array of 3 element :-  200
Enter the array of 4 element :-  250
Enter the array of 5 element :-  650
Enter number to search in list :-  200
200 was found at index 3.```

### Linear search program in python using recursion

```# python program for linear search using for loop
#define list
lst = []
#take input list size
num = int(input("Enter size of list :- "))
for n in range(num):
#append element in list/array
numbers = int(input("Enter the array of %d element :- " %n))
lst.append(numbers)
#take input number to be find in list
x = int(input("Enter number to search in list :- "))
# Recursive function to linear search x in arr[l..r]
def recLinearSearch( arr, l, r, x):
if r < l:
return -1
if arr[l] == x:
return l
if arr[r] == x:
return r
return recLinearSearch(arr, l+1, r-1, x)

res = recLinearSearch(lst, 0, len(lst)-1, x)

if res != -1:
print('{} was found at index {}.'.format(x, res))
else:
```

After executing the program, the output will be:

```Enter size of list :-  5
Enter the array of 0 element :-  14
Enter the array of 1 element :-  25
Enter the array of 2 element :-  63
Enter the array of 3 element :-  42
Enter the array of 4 element :-  78
Enter number to search in list :-  78
78 was found at index 4.```