Generate an inverted hollow right angled triangle with alphabets

In this shot, we will discuss how to generate an inverted hollow right-angled triangle with alphabets in Python.

We can print a plethora of patterns using python. The basic and only prerequisite for the same is a good understanding of how loops work in Python. Here we will be using simple for loops to generate an inverted hollow right-angled triangle using alphabets.

Description

A triangle is said to be right-angled if it has an angle equal to 90 degrees on its left side. An inverted right-angled triangle is just the inverted form of the same with its vertex lying on the bottom.

To execute the same using Python programming, we will be using 2 for loops:

  • An outer loop: To handle the number of rows.
  • An inner loop: To handle the number of columns.

Code

Let’s take a look at the code snippet below.

# Number of rows
n = 8
# Loop through rows
for i in range(1,n+1):
    
    # Loop through columns
    for j in range(1, n+1):
        ch = chr(64+i)
        # Printing Pattern
        if (i==n-j+1) or (j==1) or (i==1):
            print(ch, end=" ")
        else:
            print(" ", 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 a for loop to iterate through the number of rows.

  • In line 8, we create an inner nested for loop to iterate through the number of columns.

  • In line 9, we define ch which is used to create alphabets from numbers by using the iterative value of i and the concept of ASCII conversion. The starting value 64 + (i=1), has been used as ASCII value of A (starting of the triangle) is 65.

  • From lines 11 to 14, we create the pattern using conditional statements.

    • i== n-j+1 ⇒ creates the hypotenuse of the triangle.
    • j==1 ⇒ creates the perpendicular of the triangle.
    • i==1 ⇒ creates the base of the triangle.

  • The end statement helps to stay on the same line.

  • In line 15, the print() statement is used to move to the next line.

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