CSCSEC151: Python Programming (Lab Notes)

Lab Objectives

This practical part aims to:

Provide hands-on experience with Python code.
Practice fundamental concepts like variables, data types, loops, conditionals, and functions.
Introduce Python libraries for solving complex problems, including data manipulation and visualization [cite: 374-375].

Laboratory Programming Assignments

Assignment 1: Celsius/Fahrenheit Table

Task: Using a loop, print a table of Celsius/Fahrenheit equivalences from 0 to 100.

Logic

The formula is F = (C * 9/5) + 32.

 print("Celsius | Fahrenheit") print("-----------------------") for c in range(0, 101): f = (c * 9/5) + 32 print(f"{c:7} | {f:10.1f}")

Assignment 2: Sin/Cos/Tan Table

Task: Using a while loop, produce a table of sins, cosines, and tangents for x from 0 to 10 in steps of 0.2.

Logic

You must import the math module.

 import math print("x | sin(x) | cos(x) | tan(x)") print("--------------------------------------") x = 0.0 while x <= 10.0: s = math.sin(x) c = math.cos(x) t = math.tan(x) print(f"{x:.1f} | {s:+.4f} | {c:+.4f} | {t:+.4f}") x += 0.2

Assignment 3: Leap Year

Task: Read an integer and print "leap year" or "not a leap year".

Logic

A leap year is divisible by 4, except for years divisible by 100, unless they are also divisible by 400.

 year = int(input("Enter a year: ")) if (year % 400 == 0) or (year % 100 != 0 and year % 4 == 0): print(f"{year} is a leap year.") else: print(f"{year} is not a leap year.")

Assignments 4 & 5: Pattern Printing [cite: 383, 385-389]

Task: Take a number n and print a pattern (e.g., a triangle of stars).

Logic

This uses nested loops. The outer loop controls the rows, the inner loop controls the columns.

 n = 5 for i in range(1, n + 1): for j in range(i): print("*", end="") print() # Newline

Assignment 6: Series Calculation [cite: 390-391]

Task: Write a function that takes n and calculates 1 + 1/1! + 1/2! + ... + 1/n!

Logic

 import math def calculate_series(n): total_sum = 1.0 for i in range(1, n + 1): total_sum += 1 / math.factorial(i) return total_sum print(calculate_series(5))

Assignments 7 & 8: Factorial & Palindrome [cite: 392-393]

Task 7: Write a function to calculate the factorial of an integer.

Task 8: Write a function to check if a string is a palindrome.

Logic

 def factorial(n): if n == 0: return 1 result = 1 for i in range(1, n + 1): result *= i return result def is_palindrome(s): # s[::-1] creates a reversed copy of the string return s == s[::-1] print(factorial(5)) print(is_palindrome("racecar")) print(is_palindrome("hello"))

Assignments 9-14: Basic Problems [cite: 394-399]

(9) String to list: list('abc') gives ['a', 'b', 'c'].
(10) Fibonacci: Use an iterative approach (see theory notes).
(11) Even/Odd: Use the modulus operator: if num % 2 == 0:
(12) Compare 3 numbers: Use if/elif/else.
(13) Factors: Loop from 1 to n, check if n % i == 0.

(14) GCD: Use the Euclidean algorithm.

 def gcd(a, b): while b: a, b = b, a % b return a print(gcd(48, 18))

Assignment 15: Sorting

Task: Sort a list using Insertion, Bubble, and Selection sort.

Logic

 def bubble_sort(arr): n = len(arr) for i in range(n): for j in range(0, n - i - 1): if arr[j] > arr[j + 1]: arr[j], arr[j + 1] = arr[j + 1], arr[j] return arr # (Implement selection_sort and insertion_sort similarly)

Assignments 16 & 17: File/Exception Handling & Strings [cite: 401-402]

Task 16: Problems related to file handling and exceptions.

Task 17: Problems related to string manipulations.

Logic

 # Exception Handling try: f = open("non_existent_file.txt", "r") print(f.read()) except FileNotFoundError: print("Error: The file was not found.") except Exception as e: print(f"An error occurred: {e}") # String Manipulation s = " Hello, World! " print(s.strip()) # "Hello, World!" print(s.split(',')) # [' Hello', ' World! '] print(s.upper()) # " HELLO, WORLD! "

Assignment 18: Plotting

Task: Write a program to draw a line, bar, histogram, pie chart, etc.

Logic

Requires matplotlib. (Run pip install matplotlib first).

 import matplotlib.pyplot as plt # --- Bar Chart --- labels = ['A', 'B', 'C'] values = [10, 40, 20] plt.bar(labels, values) plt.title("Bar Chart") plt.show() # --- Pie Chart --- sizes = [15, 30, 45, 10] plt.pie(sizes, labels=['Frogs', 'Hogs', 'Dogs', 'Logs'], autopct='%1.1f%%') plt.title("Pie Chart") plt.show()