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1. Print Numbers 1–1002. Print Even Numbers in Range3. Print Odd Numbers in Range4. Sum of Digits5. Reverse Digits of a Number6. Calculate Factorial (Loop)7. Fibonacci Series8. Palindrome Number Check9. Count Digits in a Number10. GCD of Two Numbers (Loop)11. LCM of Two Numbers (Loop)12. Print Prime Numbers in Range13. Count Prime Numbers in Range14. Check Composite Number15. Power of 2 Checker16. Print Number Pattern17. Print Star Pattern18. Armstrong Numbers in Range19. Strong Numbers in Range20. Sum of Series 1/1 + 1/2 + … + 1/N21. Print Multiplication Series22. Print Pyramid Pattern23. Print Inverted Pyramid Pattern24. Print Floyd's Triangle25. Print Pascal's Triangle

Print Number Pattern in Python

Print a basic right-angled triangle number pattern using nested loops.

BeginnerLoop ProgramsExample 16 of 25
print-number-pattern.py
1# Program to print a right-angled number triangle
2

3rows = int(input("Enter number of rows: "))
4

5for i in range(1, rows + 1):
6    for j in range(1, i + 1):
7        print(j, end=" ")
8    print()

Output

Enter number of rows: 4
1 
1 2 
1 2 3 
1 2 3 4

What's going on

We use nested loops: the outer loop controls rows and the inner loop prints numbers from 1 up to the row index.

After this program

If the idea is still fuzzy, read Day 9: Loops and Iteration in the Python course. For a short check, try the Python quiz (300 questions). Stay with all 25 loop programs, or see every topic on Python exercises.

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