"""

This module uses Python 3.8's a new feature

'math.comb'

to calculate Pascal's Triangle (https://en.wikipedia.org/wiki/Pascal%27s_triangle)

and prints it into standard output

e.g.

1

1 1

1 2 1

1 3 3 1

1 4 6 4 1

1 5 10 10 5 1

1 6 15 20 15 6 1

1 7 21 35 35 21 7 1

1 8 28 56 70 56 28 8 1

1 9 36 84 126 126 84 36 9 1

"""

import math

import sys

import logging

def bin_expans(row, col):

"""

Calculate binomial coefficient

"""

nCr = math.comb(row, col)

return nCr

def build_triangle(rows = 10):

"""

Calculate triangle

"""

triangle = [[str(bin_expans(row, col))

for col in range(row+1)]

for row in range(rows)]

return triangle

def print_nicely(pascal_triangle):

"""

Print a Pascal's Triangle

iterable of iterables i.e. line and col

"""

for _row in pascal_triangle:

str_row = " ".join(_row)

last_row_len = len(" ".join(pascal_triangle[len(pascal_triangle)-1]))

print(str_row.center(last_row_len, ' '))

if __name__ == "__main__":

# Extract Python version info

ver_major, ver_minor, _, _, _ = sys.version_info

# Check if version is correct: should be above 3.8

if (ver_major*10 + ver_minor) < 38:

logger = logging.getLogger(__name__)

logging.warning("**** Python version must be above or equal to 3.8 for this module to work "

"as it uses a new math's modules Combinatorial (math.comb) API ****")

exit()

# Check if a line argument is supplied and is valid

no_of_rows = sys.argv[1] if len(sys.argv) > 1 and sys.argv[1].isdigit() else 10

# Build and print

pascal_triangle = build_triangle(int(no_of_rows))

print_nicely(pascal_triangle)