Add armstrong number checker by amandapanda00.

week1_projects/amandapanda00/armstrong_number_checker/README.md

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+Amandapanda00 – Armstrong Number Checker
+What the project does: 
+This project determines whether a given integer is an Armstrong number. An Armstrong number is a number that is equal to the sum of its digits, each raised to the power of the number of digits. (153 = 1³ + 5³ + 3³ = 153).
+
+The program allows you to:
+
+* Enter numbers directly from the keyboard, or
+
+* Read and process multiple numbers from a file.
+
+It includes proper error handling, file-processing safety, and clear output formatting.
+
+How to run it:
+1. Make sure Python is installed on your computer.
+2. Clone or download this repository.
+3. Open the project in an environment that supports Python such as VS code or PyCharm.
+4. Run the `main.py` file.
+5. When prompted, choose an input method:
+
+* Keyboard input: Enter a number directly.
+
+* File input: Enter a filename to check numbers from a file (e.g., numbers.txt). 
+  The program will read each line and check if it is an Armstrong number. 
+  Invalid lines are skipped with a message for the user.
+
+Example input/output
+
+Example Input:
+
+153
+
+Expected Output:
+
+153 is an Armstrong number
+
+Another Example:
+
+numbers.txt file
+
+Line 1: abc: Raises a ValueError when converting to int. The program prints:
+Invalid entry on line 1: 'abc'
+
+Line 2: 123 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+123 is not an Armstrong number.
+
+Line 3: 153 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+153 is an Armstrong number.
+
+Line 4: 370 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+370 is an Armstrong number.
+
+Line 5: 456 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+456 is not an Armstrong number.
+
+Line 6: xyz  Raises a ValueError. Output:
+Invalid entry on line 6: 'xyz'
+
+Line 7: 9474 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+9474 is an Armstrong number.
+
+Line 8: -45 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+-45 is not an Armstrong number.
+
+Line 9: -153 = Successfully converted to an integer. Checked by is_armstrong(). Output:
+-153 is not an Armstrong number.
+
+This file demonstrates:
+
+* Try/except blocks catching invalid data (abc and xyz).
+
+* Data integrity: only valid numbers are processed. File "r" read only.
+
+* File handling: reads multiple lines from a file.
+
+
+Error Handling
+
+try/except blocks are used to handle invalid input/value errors.
+
+* This ensures the program is not going to crash if a user enters a non-integer value.
+
+* When reading a file, invalid entries are skipped, and the line number is reported to help track and identify errors.
+
+* File handling is done with "r" mode (read-only) to protect the file and prevent accidental changes.
+
+
+Testing
+
+* PyCharm Debugger: Used to step through code and verify logic.
+
+* Pytest: Automatically tests the functionality of the Armstrong Number Checker, including both keyboard input and file input. Ensures that the program behaves     correctly for a variety of cases.
+
+* Flake8: Checks code against Python style guidelines (PEP 8).
+
+* Pydocstyle: Checks that documentation is complete and clear, ensuring maintainability.
+
+Updates Included in This Version
+
+1. process_result() now returns a string instead of printing directly. This improves testability and separation of concerns.
+
+2. main() is updated so all printing happens in one place, following recommended best practices.
+
+3. Improved documentation for clarity.
+
+4. Updated file-processing function to include:
+* Files are opened using encoding="utf-8" to ensure proper handling of characters in different environments and locales.
+
+* This prevents issues with non-ASCII characters and ensures consistent behavior across operating systems.
+
+
+Future Improvements / Suggestions
+
+Here are recommended enhancements that could be added:
+
+
+* Add GUI version 
+
+* Limit maximum allowed digits/value to avoid CPU/memory DoS from huge inputs and report if input is too large.
+
+* Expand pytest coverage to include file-processing tests
+
+* Add a GitHub Actions workflow 
+
+
+

week1_projects/amandapanda00/armstrong_number_checker/main.py

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+# Armstrong Number Checker
+# Author: amandapanda00
+# Date: 11/04/2025
+"""
+This program checks whether a given integer is an Armstrong number.
+
+An Armstrong number is equal to the sum of its digits each raised
+to the power of the number of digits.
+"""
+
+
+def is_armstrong(number):
+    """
+    Determine whether a given integer is an Armstrong number.
+
+    An Armstrong number equals the sum of its digits raised to the power
+    of the number of digits. Negative numbers automatically return False.
+
+    Parameter:
+        number (int): The integer to be tested.
+
+    Returns:
+        bool: True if the number is an Armstrong number, False otherwise.
+    """
+    if number < 0:
+        return False  # negative numbers are not Armstrong numbers
+
+    digits = [int(d) for d in str(number)]
+    n = len(digits)
+    total = sum(d ** n for d in digits)
+    return total == number
+
+
+def process_result(number):
+    """Return the formatted Armstrong result string."""
+    if is_armstrong(number):
+        return f"{number} is an Armstrong number."
+    else:
+        return f"{number} is not an Armstrong number."
+
+
+def process_file(filename="numbers.txt"):
+    """
+    Read lines from a file and test each entry to determine whether it
+    is an Armstrong number.
+
+    Invalid lines and empty lines are skipped with an explanation.
+    """
+    try:
+        with open(filename, "r", encoding="utf-8") as file:
+            for line_num, line in enumerate(file, start=1):
+                line = line.strip()
+
+                if line:
+                    try:
+                        number = int(line)
+                        result = process_result(number)
+                        print(result)
+                    except ValueError:
+                        print(f"Invalid entry on line {line_num}: '{line}'")
+
+    except FileNotFoundError:
+        print(f"Error: File '{filename}' not found.")
+    except PermissionError:
+        print(f"Error: Not allowed to read '{filename}'.")
+
+
+def main():
+    """Run the main program menu and input handling."""
+    print("Choose input method:")
+    print("1. Enter a number using the keyboard")
+    print("2. Read a number from a file")
+
+    choice = input("Enter choice (1 or 2): ").strip()
+
+    if choice == "1":
+        try:
+            num = int(input("Enter a number: "))
+            result = process_result(num)
+            print(result)
+        except ValueError:
+            print("Invalid input. Please enter a valid integer.")
+
+    elif choice == "2":
+        filename = input("Enter filename: ").strip()
+        process_file(filename)
+
+    else:
+        print("Invalid choice.")
+
+
+if __name__ == "__main__":
+    main()

week1_projects/amandapanda00/armstrong_number_checker/numbers.txt

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+abc
+123
+153
+370
+456
+xyz
+9474
+-45
+-153

week1_projects/amandapanda00/armstrong_number_checker/test_main.py

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+from main import is_armstrong
+
+
+def test_3_digit_armstrong():
+    assert is_armstrong(153)
+    assert not is_armstrong(123)
+
+
+def test_4_digit_armstrong():
+    assert is_armstrong(9474)
+    assert not is_armstrong(9475)
+
+
+def test_1_digit_armstrong():
+    assert is_armstrong(5)
+
+
+def test_negative_number():
+    assert not is_armstrong(-153)