Question

write a program in python to create a list of natural numbers from 1 to 50​

Answer 1

Given two numbers r1 and r2 (which defines the range), write a Python program to create a list with the given range (inclusive).

Examples:

Input : r1 = -1, r2 = 1

Output : [-1, 0, 1]

Input : r1 = 5, r2 = 9

Output : [5, 6, 7, 8, 9]

Let’s discuss a few approaches to do this task.

Approach #1 : Naive Approach

A naive method to create list within a given range is to first create an empty list and append successor of each integer in every iteration of for loop.

# Python3 Program to Create list  

# with integers within given range  

 

def createList(r1, r2):  

 

   # Testing if range r1 and r2  

   # are equal  

   if (r1 == r2):  

       return r1  

 

   else:  

 

       # Create empty list  

       res = []  

 

       # loop to append successors to  

       # list until r2 is reached.  

       while(r1 < r2+1 ):  

             

           res.append(r1)  

           r1 += 1

       return res  

     

# Driver Code  

r1, r2 = -1, 1

print(createList(r1, r2))  

Output:

[-1, 0, 1]

# Python3 Program to Create list  

# with integers within given range  

 

def createList(r1, r2):  

   return [item for item in range(r1, r2+1)]  

     

# Driver Code  

r1, r2 = -1, 1

print(createList(r1, r2))  

Output:

[-1, 0, 1]