In Python, for loop is used to print the a number patterns. Printing the quite a number patterns are most common asked programming questions in the interview. The a couple of for loops are used to print the patterns the place the first outer loop is used to print the wide variety of rows, and the internal loop is used to print the variety of columns. Most of the patterns use the following concepts.
The outer loop to print the number of rows.
The inner loops to print the number of columns.
The variable to print whitespace according to the required place in Python.
In this tutorial, we will discuss a few common patterns.
Print Pyramid, Star, and diamond sample in Python
In this section, we will research the frequent pyramid patterns.
Pattern – 1: Simple pyramid pattern
Example –
# This is the example of print simple pyramid pattern
n = int(input("Enter the number of rows"))
# outer loop to handle number of rows
for i in range(0, n):
# inner loop to handle number of columns
# values is changing according to outer loop
for j in range(0, i + 1):
# printing stars
print("* ", end="")
# ending line after each row
print()
Output:
*
* *
* * *
* * * *
* * * * *Explanation:
In the above code, we have initialized the n variable to enter the variety of rows for the pattern. We entered n = 5, the vary of outer for loop will be 0 to four
The iteration of the inner for loop depends on the outer loop. The inner loop is responsible to print the number of columns.
In the first iteration, the value of i is 0, and it increased by 1, so it becomes 0+1, now inner loop iterated first time and print one star(*).
In the second iteration, the value of i is 1 and it increased by 1, so it becomes 1+1, now inner loop iterated two times and print two-star (*).
The end argument prevents to jump into another line. It will printer the star until the loop is valid.
The last print statement is responsible for ending the line after each row.
Pattern – 2: Reverse right angle pyramid
Example –
# This is the example of print simple reversed right angle pyramid pattern
rows = int(input("Enter the number of rows:"))
k = 2 * rows - 2 # It is used for number of spaces
for i in range(0, rows):
for j in range(0, k):
print(end=" ")
k = k - 2 # decrement k value after each iteration
for j in range(0, i + 1):
print("* ", end="") # printing star
print("")
Output:
*
* *
* * *
* * * *
* * * * *Pattern – 3: Printing Downward half – Pyramid
Code –
rows = int(input("Enter the number of rows: "))
# the outer loop is executing in reversed order
for i in range(rows + 1, 0, -1):
for j in range(0, i - 1):
print("*", end=' ')
print(" ")
Output:
Enter the number of rows: 5
* * * * *
* * * *
* * *
* *
* Pattern – 4: Printing Triangle Pyramid
Code –
n = int(input("Enter the number of rows: "))
m = (2 * n) - 2
for i in range(0, n):
for j in range(0, m):
print(end=" ")
m = m - 1 # decrementing m after each loop
for j in range(0, i + 1):
# printing full Triangle pyramid using stars
print("* ", end=' ')
print(" ")
Output:
Enter the number of rows: 10
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * * * * Pattern – 5: Downward Triangle Pattern
Code –
rows = int(input("Enter the number of rows: "))
# It is used to print space
k = 2 * rows - 2
# Outer loop in reverse order
for i in range(rows, -1, -1):
# Inner loop will print the number of space.
for j in range(k, 0, -1):
print(end=" ")
k = k + 1
# This inner loop will print the number o stars
for j in range(0, i + 1):
print("*", end=" ")
print("")
Output:
* * * * * * * * * * *
* * * * * * * * * *
* * * * * * * * *
* * * * * * * *
* * * * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
*Pattern – 6: Diamond Shaped Pattern
Code –
rows = int(input("Enter the number of rows: "))
# It is used to print the space
k = 2 * rows - 2
# Outer loop to print number of rows
for i in range(0, rows):
# Inner loop is used to print number of space
for j in range(0, k):
print(end=" ")
# Decrement in k after each iteration
k = k - 1
# This inner loop is used to print stars
for j in range(0, i + 1):
print("* ", end="")
print("")
# Downward triangle Pyramid
# It is used to print the space
k = rows - 2
# Output for downward triangle pyramid
for i in range(rows, -1, -1):
# inner loop will print the spaces
for j in range(k, 0, -1):
print(end=" ")
# Increment in k after each iteration
k = k + 1
# This inner loop will print number of stars
for j in range(0, i + 1):
print("* ", end="")
print("")
Output:
Enter the number of rows: 8
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * * *
* * * * * * * * *
* * * * * * * *
* * * * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
*Pattern – 7: Print two pyramid in a single sample
Code –
rows = input("Enter the number of rows: ")
# Outer loop will print the number of rows
for i in range(0, rows):
# This inner loop will print the stars
for j in range(0, i + 1):
print("*", end=' ')
# Change line after each iteration
print(" ")
# For second pattern
for i in range(rows + 1, 0, -1):
for j in range(0, i - 1):
print("*", end=' ')
print(" ")
Output:
Enter the number of rows: 7
*
* *
* * *
* * * *
* * * * *
* * * * * *
* * * * * * *
* * * * * * *
* * * * * *
* * * * *
* * * *
* * *
* *
*Pattern – 8: Hourglass Pattern
Code –
rows = int(input("Enter the number of rows: "))
k = rows - 2
# This is used to print the downward pyramid
for i in range(rows, -1 , -1):
for j in range(k , 0 , -1):
print(end=" ")
k = k + 1
for j in range(0, i+1):
print("* " , end="")
print()
# This is used to print the upward pyramid
k = 2 * rows - 2
for i in range(0 , rows+1):
for j in range(0 , k):
print(end="")
k = k - 1
for j in range(0, i + 1):
print("* ", end="")
print()
Output:
Enter the number of rows: 5
* * * * * *
* * * * *
* * * *
* * *
* *
*
*
* *
* * *
* * * *
* * * * *
* * * * * *We have discussed the primary pyramid sample the usage of for loops. The idea of the sample depends on the good judgment and acceptable use of for loop.
Number Pattern in Python
In this section, we describe a few packages of exclusive kinds of quantity patterns. Let’s apprehend the following patterns one by way of one.
Pattern – 1: Number Pattern
Code –
rows = int(input("Enter the number of rows: "))
# Outer loop will print number of rows
for i in range(rows+1):
# Inner loop will print the value of i after each iteration
for j in range(i):
print(i, end=" ") # print number
# line after each row to display pattern correctly
print(" ")
Output:
Enter the number of rows: 5
1
2 2
3 3 3
4 4 4 4
5 5 5 5 5 Explanation –
In the above code, we have printed the numbers according to rows value. The first row prints a single number. Next, two numbers, prints in the second row, and the next three number prints on the third row and so on. In the
Pattern – 2: Half pyramid pattern with the number
Code –
rows = int(input("Enter the number of rows: "))
# This will print the rows
for i in range(1, rows+1):
# This will print number of column
for j in range(1, i + 1):
print(j, end=' ')
print("")
Output:
Enter the number of rows: 5
1
1 2
1 2 3
1 2 3 4
1 2 3 4 5In the above code, we have printed the column value j in the internal for loop.
Pattern – 3: Inverted Pyramid Pattern
Code –
rows = int(input("Enter the number of rows: 5"))
k = 0
# Reversed loop for downward inverted pattern
for i in range(rows, 0, -1):
# Increment in k after each iteration
k += 1
for j in range(1, i + 1):
print(k, end=' ')
print()
Output:
Enter the number of rows: 5
1 1 1 1 1
2 2 2 2
3 3 3
4 4
5Explanation:
In the above code, we have used the reversed loop to print the downward inverted pyramid the place quantity reduced after every iteration.
Pattern – 4: Same number Inverted Pyramid
Code –
rows = int(input("Enter the number of rows: "))
# rows value assign to n variable
n = rows
# Download reversed loop
for i in range(rows, 0, -1):
for j in range(0, i):
# this will print the same number
print(n, end=' ')
print()
Output:
Enter the number of rows: 6
6 6 6 6 6 6
6 6 6 6 6
6 6 6 6
6 6 6
6 6
6Pattern – 5: Descending Order of Number
Code –
rows = int(input("Enter the number of rows: "))
# Downward loop for inverse loop
for i in range(rows, 0, -1):
n = i # assign value to n of i after each iteration
for j in range(0, i):
# print reduced value in each new line
print(n, end=' ')
print("\r")
Output:
Enter the number of rows: 6
6 6 6 6 6 6
5 5 5 5 5
4 4 4 4
3 3 3
2 2
1Pattern – 6: Print 1 to 10 numbers in Pattern
Code –
current_Number = 1
stop = 2
rows = 3 # Number of rows to print numbers
for i in range(rows):
for j in range(1, stop):
print(current_Number, end=' ')
current_Number += 1
print("")
stop += 2
Output:
1
2 3 4
5 6 7 8 9Pattern – 7: Reverse Pattern from 10 to 1
Code –
rows = int(input("Enter the number of rows: "))
for i in range(0, rows + 1):
# inner loop for decrement in i values
for j in range(rows - i, 0, -1):
print(j, end=' ')
print()
Output:
Enter the number of rows: 6
6 5 4 3 2 1
5 4 3 2 1
4 3 2 1
3 2 1
2 1
1Pattern – 8: Print Odd Numbers
Code –
rows = int(input("Enter the number of rows: "))
i = 1
# outer file loop to print number of rows
while i <= rows:
j = 1
# Check the column after each iteration
while j <= i:
# print odd values
print((i * 2 - 1), end=" ")
j = j + 1
i = i + 1
print()
Output:
Enter the number of rows: 5
1
3 3
5 5 5
7 7 7 7
9 9 9 9 9Pattern – 9: Square Pattern using with number
Code –
rows = int(input("Enter the number of rows: "))
for i in range(1, rows + 1):
for j in range(1, rows + 1):
# Check condition if value of j is smaller or equal than
# the j then print i otherwise print j
if j <= i:
print(i, end=' ')
else:
print(j, end=' ')
print()
Output:
Enter the number of rows: 5
1 2 3 4 5
2 2 3 4 5
3 3 3 4 5
4 4 4 4 5
5 5 5 5 5Pattern – 10: Multiplication Number in Column
rows = int(input("Enter the number of rows: "))
for i in range(1, rows):
for j in range(1, i + 1):
# It prints multiplication or row and column
print(i * j, end=' ')
print()
Output:
Enter the number of rows: 8
1
2 4
3 6 9
4 8 12 16
5 10 15 20 25
6 12 18 24 30 36
7 14 21 28 35 42 49 In the above section, we have mentioned all the basic variety patterns. It will make a strong command on Python for loop. We can any kind of sample using for loop.
Alphabets and Letters Pattern in Python
As we comprehend that the, every alphabet has its own ASCII value, so define a persona and print it to the screen. Let’s apprehend these patterns via following examples
Pattern – 1: Right-angled pattern with characters
Code –
print("The character pattern ")
asciiValue = 65 #ASCII value of A
for i in range(0, 5):
for j in range(0, i + 1):
# It will convert the ASCII value to the character
alphabate = chr(asciiValue)
print(alphabate, end=' ')
asciiValue += 1
print()
Output:
The character pattern
A
B C
D E F
G H I J
K L M N OExplanation –
In the above code, we have assigned the integer cost 65 to asciiValue variable which is an ASCII fee of A. We described for loop to print 5 rows. In the internal loop body, we transformed the ASCII price into the character the use of the char() function. It will print the alphabets, increased the asciiValue after each iteration.
Pattern – 2: Right-angled Pattern with Same Character
Code –
print("The character pattern ")
asciiValue = int(input("Enter the ASCII value to print pattern: "))
# User - define value
if (asciiValue >= 65 or asciiValue <=122):
for i in range(0, 5):
for j in range(0, i + 1):
# It will convert the ASCII value to the character
alphabate = chr(asciiValue)
print(alphabate, end=' ')
print()
else:
print("Enter the valid character value")
Output:
The character pattern
Enter the ASCII value to print pattern: 75
K
K K
K K K
K K K K
K K K K KPattern – 3: Display letter of the phrase in Pattern
Code –
str1 = "JavaTpoint"
x = ""
for i in str1:
x += i
print(x)
Output:
J
Ja
Jav
Java
JavaT
JavaTp
JavaTpo
JavaTpoi
JavaTpoin
JavaTpointWe can use any word to print the characters.
Pattern – 5: Equilateral triangle sample with characters
Code –
print("Print equilateral triangle Pyramid with characters ")
s = 5
asciiValue = 65
m = (2 * s) - 2
for i in range(0, s):
for j in range(0, m):
print(end=" ")
# Decreased the value of after each iteration
m = m - 1
for j in range(0, i + 1):
alphabate = chr(asciiValue)
print(alphabate, end=' ')
# Increase the ASCII number after each iteration
asciiValue += 1
print()
Output:
Print equilateral triangle Pyramid with characters
A
B C
D E F
G H I J
K L M N OIn this article, we have mentioned all primary sample programs. These patterns are frequently requested during the interview and it is also helpful to understand the thinking of Python for loop. Once we get the good judgment of the program, we can print the any sample using the Python loops.