Patterns can be printed in python using simple for loops. First outer loop is used to handle the number of rows and the Inner nested loop is used to handle the number of columns. Manipulating the print statements, different number patterns, alphabet patterns, or star patterns can be printed.
Some of the Patterns are shown in this article.
- Simple pyramid pattern
Python3
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing patterndef pypart(n): # outer loop to handle number of rows # n in this case for i in range(0, n): # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # printing stars print("* ",end="") # ending line after each row print("\r")# Driver Coden = 5pypart(n) |
* * * * * * * * * * * * * * *
Time Complexity: O(n2),This algorithm has a time complexity of O(n2). This is because the outer loop runs n times and the inner loop runs n times for each iteration of the outer loop, resulting in a total of n2 iterations.
Space Complexity: O(1),This algorithm has a space complexity of O(1). This is because there are no auxiliary data structures (such as arrays or lists) used, only primitives and constants.
Approach 2: Using List in Python 3, this could be done in a simpler way
Python
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing patterndef pypart(n): myList = [] for i in range(1,n+1): myList.append("*"*i) print("\n".join(myList))# Driver Coden = 5pypart(n) |
* ** *** **** *****
Time Complexity: O(n) ,The time complexity of this code is O(n), as it iterates through a loop of size n, where n is the number of stars to be printed.
Space Complexity: O(n) ,The space complexity of this code is O(n), as the myList array is used to store the string of stars, which is of size n.
Approach 3: Using recursion
Python3
#python3 code to print pyramid pattern using recursiondef pypart(n): if n==0: return else: pypart(n-1) print("* "*n) # Driver Coden = 5pypart(n)#this code is contributed by Shivesh Kumar Dwivedi |
* * * * * * * * * * * * * * *
Approach 4: Using while loop
Python3
# python3 code to print pyramid pattern using while loop# inputn=5i=1;j=0# while loop check the condition until the# condition become false. if it is true then# enter in to loop and print the patternwhile(i<=n): while(j<=i-1): print("* ",end="") j+=1 # printing next line for each row print("\r") j=0;i+=1 # this code is contributed by gangarajula laxmi |
* * * * * * * * * * * * * * *
The time complexity of the given code is O(n^2), where n is the input size.
Space complexity is O(1).
Approach 5: Using for loops
Python3
n = 5for i in range(0, n): for j in range(0, i+1): print("*", end=" ") print() |
* * * * * * * * * * * * * * *
- After 180 degrees rotation
Python3
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing patterndef pypart2(n): # number of spaces k = 2*n - 2 # outer loop to handle number of rows for i in range(0, n): # inner loop to handle number spaces # values changing acc. to requirement for j in range(0, k): print(end=" ") # decrementing k after each loop k = k - 2 # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # printing stars print("* ", end="") # ending line after each row print("\r")# Driver Coden = 5pypart2(n) |
*
* *
* * *
* * * *
* * * * *
Optimized Solution:
Here, we have to print a space (height – row) times and then print “*” row times.
For example: let height of the pyramid is 5
then , on the row number 1 we print blank space 4 times(that is 5-1 or height -row)
and then we print star 1 time(that is row times) and then a new line
then , on the row number 2 we print blank space 3 times(that is 5-2 or height -row)
and then we print star 2 times (that is row times) and then a new line
and so on….
Method: Using while loop
Python3
# python3 code to print pyramid pattern using while loopn=5;i=0while(i<=n): print(" " * (n - i) +"*" * i) i+=1 |
*
**
***
****
*****
Method: Using for loop
Python3
#python3 code to implement above approachheight = 5for row in range(1, height+ 1): print(" " * (height - row) +"*" * row)#this code is contributed by Shivesh kumar dwivedi |
* ** *** **** *****
- Printing Triangle
Python3
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing pattern triangledef triangle(n): # number of spaces k = n - 1 # outer loop to handle number of rows for i in range(0, n): # inner loop to handle number spaces # values changing acc. to requirement for j in range(0, k): print(end=" ") # decrementing k after each loop k = k - 1 # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # printing stars print("* ", end="") # ending line after each row print("\r")# Driver Coden = 5triangle(n) |
* * * * * * * * * * * * * * *
- Number Pattern
Python3
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing pattern of numbersdef numpat(n): # initialising starting number num = 1 # outer loop to handle number of rows for i in range(0, n): # re assigning num num = 1 # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # printing number print(num, end=" ") # incrementing number at each column num = num + 1 # ending line after each row print("\r")# Driver coden = 5numpat(n) |
1 1 2 1 2 3 1 2 3 4 1 2 3 4 5
- Numbers without reassigning
Python3
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing pattern of numbersdef contnum(n): # initializing starting number num = 1 # outer loop to handle number of rows for i in range(0, n): # not re assigning num # num = 1 # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # printing number print(num, end=" ") # incrementing number at each column num = num + 1 # ending line after each row print("\r")n = 5# sending 5 as argument# calling Functioncontnum(n) |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
- Character Pattern
Python3
# Python 3.x code to demonstrate star pattern# Function to demonstrate printing pattern of alphabetsdef alphapat(n): # initializing value corresponding to 'A' # ASCII value num = 65 # outer loop to handle number of rows # 5 in this case for i in range(0, n): # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # explicitly converting to char ch = chr(num) # printing char value print(ch, end=" ") # incrementing number num = num + 1 # ending line after each row print("\r")# Driver Coden = 5alphapat(n) |
A B B C C C D D D D E E E E E
- Continuous Character pattern
Python3
# Python code 3.x to demonstrate star pattern# Function to demonstrate printing pattern of alphabetsdef contalpha(n): # initializing value corresponding to 'A' # ASCII value num = 65 # outer loop to handle number of rows- for i in range(0, n): # inner loop to handle number of columns # values changing acc. to outer loop for j in range(0, i+1): # explicitly converting to char ch = chr(num) # printing char value print(ch, end=" ") # incrementing at each column num = num + 1 # ending line after each row print("\r")# Driver coden = 5contalpha(n) |
Output:
A B C D E F G H I J K L M N O
- Character Triangle
Python3
n = 5alph = 65for i in range(0, n): print(" " * (n-i), end=" ") for j in range(0, i+1): print(chr(alph), end=" ") alph += 1 alph = 65 print() |
A
A B
A B C
A B C D
A B C D E
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