When n = 5 the pattern must be:
1
121
12321
121
1
What I tried till now:
# Pattern 1-121-12321 pyramid pattern
# Reading number of rows
row = int(input('Enter how many lines? '))
# Generating pattern
for i in range(1,row+1):
# for space
for j in range(1, row+1-i):
print(' ', end='')
# for increasing pattern
for j in range(1,i+1):
print(j, end='')
# for decreasing pattern
for j in range(i-1,0,-1):
print(j, end='')
# Moving to next line
print()
Output I am getting:
1
121
12321
1234321
123454321
I know the logic for similar such patterns like:
*
***
*****
*******
But the number pattern seems to be confusing and I am not able to get the logic.
Python Program for generating the following Pattern for printing n rows:
eg. When n=7:
1
121
12321
1234321
12321
121
1
How about this code:
for i in range(n):
temp = 0 # Store the value of the number to square (so 1, 11,...)
if (i < n / 2):
for j in range(i + 1):
temp += 10 ** j # Construct the number (1 = 1, 11 = 1 + 10, 111 = 1 + 10 + 10 ^ 2,...)
for _ in range(int(n / 2 - i)):
print(' ', end = '') # Add space indentation
else:
for j in range(n - i): # Count in reverse now
temp += 10 ** j # Construct the number (1 = 1, 11 = 1 + 10, 111 = 1 + 10 + 10 ^ 2,...)
for _ in range(int(i - n / 2) + 1):
print(' ', end = '') # Add space indentation
print(temp ** 2) # Square the temporary value
(Fun mathematical fact: the string you print have a property of:
1 = 1 ^ 2; 121 = 11 ^ 2; 12321 = 111 ^ 2;...)
I will also give my suggestion. So here I initially just outsource the production of the line into a method. I first calculate the length of the current line and depending on the maximum number of lines you want to print determine the padding to get this star shape. Then I produce the actual string, which is dependent on the middle point of the string, so as soon as I exceed this, I decrease the numbering again.
from math import ceil
def produce_line(line, maximum):
middle = ceil(maximum / 2)
padding = abs(middle - line)
line_width = maximum - 2 * padding
half_lw = ceil(line_width / 2)
res = (" " * padding) + "".join([str(a) if a <= half_lw else str(abs(2 * half_lw - a)) for a in range(1, line_width + 1)])
return res
lines = 9
for i in range(1, lines + 1):
print(produce_line(i, lines))
You could add an if statement and start from a count with a new variable c:
row = int(input('Enter how many lines? '))
c = row // 2
for i in range(1,row+1):
if i <= (row // 2 + 1):
# for space
for j in range(1, row+1-i):
print(' ', end='')
# for increasing pattern
for j in range(1,i+1):
print(j, end='')
# for decreasing pattern
for j in range(i-1,0,-1):
print(j, end='')
else:
for j in range(1, i):
print(' ', end='')
# for increasing pattern
for j in range(1, c):
print(j, end='')
# for decreasing pattern
for j in range(c, 0, -1):
print(j, end='')
c -= 1
# Moving to next line
print()
Output:
Enter how many lines? 7
1
121
12321
1234321
12321
121
1