Generate a left-angled triangle using numbers in Python
We can print a plethora of patterns using Python. The only prerequisite to do this is a good understanding of how loops work in Python.
Here, we will be using simple for loops to generate a left-angled triangle using numbers.
Description
A triangle is said to be left-angled if – and only if – it has one angle equal to 90 degrees on its right side.
To execute this using Python programming, we will be using two for loops nested within an outer for loop:
- Outer loop: To handle the number of rows.
- Inner loops: One to handle the initial spaces and the other to print the numbers.
Code
Let’s look at the below code snippet.
# Number of rowsrows = 5# Iterating value for columnk = 2*rows-2# Loop through rowsfor i in range(rows):# Loop to print initial spacesfor j in range(k):print(end=" ")# Updating value of Kk = k-2# Loop to print the numbersfor j in range(i+1):print(j+1, end=" ")print()
Explanation
-
In line 2, we take the input for the number of rows (i.e., length of the triangle).
-
In line 5, we create the iterating variable
k, which will be used later to handle the number of columns. -
From lines 8 to 20, we create the outer
forloop to iterate through the number of rows. -
In lines 11 and 12, we create the first inner nested loop to print the initial spaces.
-
In line 15, the value of
kis updated so that the output is a left-angled triangle, i.e., the characters are printed from right to left. Unless it is updated, the triangle will be a right-angled triangle. -
In line 18, we create our second inner nested loop to print the numbers.
-
In line 19, we printed
j+1, which results in iteration from 1 (since j + 1) to the length ofiin each row. Asikeeps increasing with increasing rows, the numbers keep increasing as the line number increases.