How do you print a full triangle in python?

Programs to print triangles using *, numbers and characters

Example 1: Program to print half pyramid using *

*
* *
* * *
* * * *
* * * * *

Source Code

rows = int[input["Enter number of rows: "]]

for i in range[rows]:
    for j in range[i+1]:
        print["* ", end=""]
    print["\n"]

In the above program, let's see how the pattern is printed.

• First, we get the height of the pyramid rows from the user.
• In the first loop, we iterate from i = 0 to i = rows.
• The second loop runs from j = 0 to i + 1. In each iteration of this loop, we print i + 1 number of * without a new line. Here, the row number gives the number of * required to be printed on that row. For example, in the 2nd row, we print two *. Similarly, in the 3rd row, we print three *.
• Once the inner loop ends, we print new line and start printing * in a new line.

Example 2: Program to print half pyramid a using numbers

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

Source Code

rows = int[input["Enter number of rows: "]]

for i in range[rows]:
    for j in range[i+1]:
        print[j+1, end=" "]
    print["\n"]

In the above program, let's see how the pattern is printed.

• First, we get the height of the pyramid rows from the user.
• In the first loop, we iterate from i = 0 to i = rows.
• In the second loop, we print numbers starting from 1 to j, where j ranges from 0 to i.
• After each iteration of the first loop, we print a new line.

Example 3: Program to print half pyramid using alphabets

A
B B
C C C
D D D D
E E E E E

Source Code

rows = int[input["Enter number of rows: "]]

ascii_value = 65

for i in range[rows]:
    for j in range[i+1]:
        alphabet = chr[ascii_value]
        print[alphabet, end=" "]
    
    ascii_value += 1
    print["\n"]

The working of the above example is also similar to the other examples discussed above except that the ascii values are printed here. The ascii value for alphabets start from 65 [i.e. A]. Therefore, in each iteration, we increase the value of ascii_value and print its corresponding alphabet.

Programs to print inverted half pyramid using * and numbers

Example 4: Inverted half pyramid using *

* * * * *
* * * *
* * *
* *
*

Source Code

rows = int[input["Enter number of rows: "]]

for i in range[rows, 0, -1]:
    for j in range[0, i]:
        print["* ", end=" "]
    
    print["\n"]

This example is similar to an upright pyramid except that here we start from the total number of rows and in each iteration we decrease the number of rows by 1.

Example 5: Inverted half pyramid using numbers

1 2 3 4 5
1 2 3 4
1 2 3
1 2
1

Source Code

rows = int[input["Enter number of rows: "]]

for i in range[rows, 0, -1]:
    for j in range[1, i+1]:
        print[j, end=" "]
    
    print["\n"]

The only difference between an upright and an inverted pyramid using numbers is that the first loop starts from the total number of rows to 0.

Programs to print full pyramids

Example 6: Program to print full pyramid using *

        *
      * * *
    * * * * *
  * * * * * * *
* * * * * * * * *

Source Code

rows = int[input["Enter number of rows: "]]

k = 0

for i in range[1, rows+1]:
    for space in range[1, [rows-i]+1]:
        print[end="  "]
   
    while k!=[2*i-1]:
        print["* ", end=""]
        k += 1
   
    k = 0
    print[]

This type of pyramid is a bit more complicated than the ones we studied above.

• The outermost loop starts from i = 1 to i = row + 1.
• Among the two inner loops, the for loop prints the required spaces for each row using formula [rows-i]+1, where rows is the total number of rows and i is the current row number.
• The while loop prints the required number stars using formula 2 * i - 1. This formula gives the number of stars for each row, where row is i.

Example 7: Full Pyramid of Numbers

        1 
      2 3 2 
    3 4 5 4 3 
  4 5 6 7 6 5 4 
5 6 7 8 9 8 7 6 5

Source Code

rows = int[input["Enter number of rows: "]]

k = 0
count=0
count1=0

for i in range[1, rows+1]:
    for space in range[1, [rows-i]+1]:
        print["  ", end=""]
        count+=1
    
    while k!=[[2*i]-1]:
        if count