PASCALS_TRIANGLE_GENERATION_TWO
The Python program featured in this tutorial web page prints the first N rows of Pascal’s Triangle to the command line terminal interface and to a plain-text output file such that the output visually resembles an isosceles triangle.
The Python program file which is featured in this tutorial web page has many common attributes with the C++ source code file featured on the tutorial web page of this website named PASCALS_TRIANGLE_GENERATION. Unlike that C++ source code file, this Python program generates slightly different output messages (to the command line terminal and to the generated and/or overwritten output file).
Pascal’s Triangle is a triangular arrangement of natural numbers (resembling an isosceles triangle) such that the top row consists solely of the number 1, each subsequent row begins and ends with 1, and every other number in the arrangement is the sum of the two numbers directly above that number.
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SOFTWARE_APPLICATION_COMPONENTS
python_source_file: https://raw.githubusercontent.com/karlinarayberinger/KARLINA_OBJECT_extension_pack_22/main/pascals_triangle_generator.py
plain_text_file: https://raw.githubusercontent.com/karlinarayberinger/KARLINA_OBJECT_extension_pack_22/main/pascals_triangle_generator_output_two.txt
PROGRAM_INTERPRETATION_AND_EXECUTION
STEP_0: Copy and paste the Python source code into a new text editor document and save that document as the following file name:
pascals_triangle_generator.py
STEP_1: Open a Unix command line terminal application and set the current directory to wherever the C++ is located on the local machine (e.g. Desktop).
cd Desktop
STEP_2: Run the program by entering the following command:
python3 pascals_triangle_generator.py
STEP_3: If the program interpretation command does not work, then use the following commands (in top-down order) to install the Python interpreter:
sudo apt update
sudo apt install python3
STEP_4: After running the Python program is booted up, the following prompt will appear:
Enter the number of rows for Pascal's Triangle:
STEP_5: Enter a value for a using the keyboard.
STEP_6: Observe program results on the command line terminal and in the output file.
PROGRAM_SOURCE_CODE
The text in the preformatted text box below appears on this web page (while rendered correctly by the web browser) to be identical to the content of the Python source code file whose Uniform Resource Locator is displayed in the green hyperlink below.
Note that, unlike C++ program files (which are compiled into machine-executable instructions before program runtime), Python program files are interpreted one line at a time instead.
python_source_file: https://raw.githubusercontent.com/karlinarayberinger/KARLINA_OBJECT_extension_pack_22/main/pascals_triangle_generator.py
#########################################################################################
# file: pascals_triangle_generation.py
# type: Python
# date: 05_OCTOBER_2024
# author: karbytes
# license: PUBLIC_DOMAIN
#########################################################################################
def generate_first_N_rows_of_pascals_triangle(N):
# Initialize Pascal's triangle as a list of lists.
pascals_triangle = [[1]]
# If N is smaller than one or larger than twenty, set N to ten.
if N < 1 or N > 20:
N = 10
# Generate each row of Pascal's Triangle.
for i in range(1, N):
row = [1] * (i + 1)
for j in range(1, i):
row[j] = pascals_triangle[i - 1][j - 1] + pascals_triangle[i - 1][j]
pascals_triangle.append(row)
return pascals_triangle
def print_pascals_triangle(pascals_triangle, output):
N = len(pascals_triangle)
# Find the width of the largest number in the last row for formatting.
max_width = len(str(pascals_triangle[N - 1][N // 2]))
# Output header to both file and console
output.write("\n\nPrinting the first {} rows of Pascal's Triangle...\n\n".format(N))
print("\n\nPrinting the first {} rows of Pascal's Triangle...\n\n".format(N))
# Print the Pascal's triangle
for i in range(N):
# Create the leading spaces for aligning the triangle shape
leading_spaces = " " * ((N - i) * (max_width + 1) // 2)
# Output leading spaces and row numbers to both file and console
output.write(leading_spaces)
print(leading_spaces, end="")
# Output each number in the current row to both file and console
row_numbers = " ".join(f"{pascals_triangle[i][j]:{max_width}}" for j in range(i + 1))
output.write(row_numbers + "\n")
print(row_numbers)
def main():
# Open the file for writing (and generate that file if it does not exist).
with open("pascals_triangle_generator_output.txt", "w") as file:
# Print an opening message to the command line terminal.
print("\n\n--------------------------------")
print("Start Of Program")
print("--------------------------------")
# Print an opening message to the output file.
file.write("--------------------------------\n")
file.write("Start Of Program\n")
file.write("--------------------------------\n")
# Print "This C++ program generates the first N rows of Pascal's Triangle." to the command line terminal and to the output file.
print("\n\nThis Python program generates the first N rows of Pascal's Triangle.")
file.write("\n\nThis Python program generates the first N rows of Pascal's Triangle.")
# Print a horizontal divider line to the command line terminal and to the output file.
print("\n\n--------------------------------")
file.write("\n\n--------------------------------")
# Prompt the user to enter an input value and store that value in N.
N = int(input("\n\nEnter the number of rows for Pascal's Triangle: "))
# Log user input to the file after it is entered.
file.write(f"\n\nEntered value: N = {N}")
print(f"\n\nEntered value: N = {N}")
# Generate Pascal's Triangle
pascals_triangle = generate_first_N_rows_of_pascals_triangle(N)
# Print Pascal's Triangle to both the output file and to the command line terminal.
print_pascals_triangle(pascals_triangle, file)
# Print a closing message to the command line terminal.
print("\n\n--------------------------------")
print("End Of Program")
print("--------------------------------\n\n")
# Print a closing message to the output file.
file.write("\n\n--------------------------------\n")
file.write("End Of Program\n")
file.write("--------------------------------\n")
# Program entry point
if __name__ == "__main__":
main()
SAMPLE_PROGRAM_OUTPUT
The text in the preformatted text box below was generated by one use case of the Python program featured in this computer programming tutorial web page.
(Note that the aforementioned Python program specifies to name the output file prime_numbers_generation_output.txt instead of prime_numbers_generation_output_two.txt (which is what the hyperlinked plain-text file below is named) because karbytes did not want the C++ program’s output file (which is named pascals_triangle_generator_output.txt) to be overwritten with the Python program output file in the GitHub repository which houses both output files and which is named KARLINA_OBJECT_extension_pack_22).
plain_text_file: https://raw.githubusercontent.com/karlinarayberinger/KARLINA_OBJECT_extension_pack_22/main/pascals_triangle_generator_output_two.txt
--------------------------------
Start Of Program
--------------------------------
This Python program generates the first N rows of Pascal's Triangle.
--------------------------------
Entered value: N = 20
Printing the first 20 rows of Pascal's Triangle...
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
1 10 45 120 210 252 210 120 45 10 1
1 11 55 165 330 462 462 330 165 55 11 1
1 12 66 220 495 792 924 792 495 220 66 12 1
1 13 78 286 715 1287 1716 1716 1287 715 286 78 13 1
1 14 91 364 1001 2002 3003 3432 3003 2002 1001 364 91 14 1
1 15 105 455 1365 3003 5005 6435 6435 5005 3003 1365 455 105 15 1
1 16 120 560 1820 4368 8008 11440 12870 11440 8008 4368 1820 560 120 16 1
1 17 136 680 2380 6188 12376 19448 24310 24310 19448 12376 6188 2380 680 136 17 1
1 18 153 816 3060 8568 18564 31824 43758 48620 43758 31824 18564 8568 3060 816 153 18 1
1 19 171 969 3876 11628 27132 50388 75582 92378 92378 75582 50388 27132 11628 3876 969 171 19 1
--------------------------------
End Of Program
--------------------------------
This web page was last updated on 05_OCTOBER_2024. The content displayed on this web page is licensed as PUBLIC_DOMAIN intellectual property.