Python Program to Print Numbers 1 to n

You can print numbers from 1 to n in Python using a for loop like this: for i in range(1, n+1): print(i).

Examples

Input1

Output1

Input5

Output1 2 3 4 5

Input0

Output

How to Think About It

To print numbers from 1 to n, start counting from 1 and go up to n, printing each number one by one. Use a loop that repeats this counting and printing until you reach n.

Algorithm

1

Get the input number n.

2

Start a counter from 1.

3

Repeat until the counter is greater than n:

4

Print the current counter value.

5

Increase the counter by 1.

Code

python

n = int(input("Enter a number: "))
for i in range(1, n + 1):
    print(i)

Output

Enter a number: 5
1
2
3
4
5

Dry Run

Let's trace the input 3 through the code

1

Input

User enters n = 3

2

Start loop

i starts at 1

3

Print i

Print 1

4

Increment i

i becomes 2

5

Print i

Print 2

6

Increment i

i becomes 3

7

Print i

Print 3

8

Increment i

i becomes 4, loop ends because 4 > 3

i
1
2
3

Why This Works

Step 1: Input number n

We get the number n from the user using input() and convert it to an integer with int().

Step 2: Loop from 1 to n

The for loop with range(1, n+1) runs from 1 up to n, including n.

Step 3: Print each number

Inside the loop, print(i) outputs the current number, showing all numbers from 1 to n.

Alternative Approaches

while loop

python

n = int(input("Enter a number: "))
i = 1
while i <= n:
    print(i)
    i += 1

Uses a while loop instead of for; slightly longer but works the same.

using list comprehension and join

python

n = int(input("Enter a number: "))
print('\n'.join(str(i) for i in range(1, n + 1)))

Prints all numbers at once by joining them with newlines; good for compact code.

Complexity: O(n) time, O(1) space

Time Complexity

The loop runs n times, printing each number once, so time grows linearly with n.

Space Complexity

Only a few variables are used, so space stays constant regardless of n.

Which Approach is Fastest?

The for loop and while loop have similar speed; list comprehension with join may be slightly slower due to string operations.

Approach	Time	Space	Best For
For loop with range	O(n)	O(1)	Simple and clear printing
While loop	O(n)	O(1)	When condition-based looping is preferred
List comprehension with join	O(n)	O(n)	Printing all at once, compact code