First Steps in Python

print("Hello World!")

$ python3
Python 3.8.5 (default, Sep  4 2020, 02:22:02)
[Clang 10.0.0 ] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> print("Hello World!")
Hello World!
>>> 2 + 3
5
>>> name = "Alice"
>>> print(f"Hello, {name}!")
Hello, Alice!
>>>

# Simple program to greet users
name = input("What's your name? ")
age = input("How old are you? ")

print(f"Hello {name}!")
print(f"You are {age} years old.")
print("Happy learning Python!")

$ python3 greeting.py
What's your name? John
How old are you? 20
Hello John!
You are 20 years old.
Happy learning Python!

# Install JupyterLab with the selected Python interpreter
python3 -m pip install jupyterlab

# Or install it from conda-forge in a Conda environment
conda install -c conda-forge jupyterlab

# Run Jupyter Lab
jupyter lab

# Will open browser with Jupyter interface

# Cell 1: Import and setup
import math

# Cell 2: Variables and operations
radius = 5
area = math.pi * radius ** 2
print(f"Circle area with radius {radius} is {area:.2f}")

# Cell 3: Create function
def calculate_circle_area(r):
  """Function to calculate circle area"""
  return math.pi * r ** 2

# Cell 4: Test function
test_radius = 7
result = calculate_circle_area(test_radius)
print(f"Circle area with radius {test_radius} is {result:.2f}")

# Basic data types in Python

# String (text)
name = "John Doe"
message = 'Hello Python!'

# Integer (whole numbers)
age = 25
year = 2025

# Float (decimal numbers)
height = 175.5
pi = 3.14159

# Boolean (True/False)
is_student = True
is_graduated = False

# List (list of items)
fruits = ["apple", "orange", "mango", "banana"]
numbers = [1, 2, 3, 4, 5]

# Dictionary (key-value pairs)
person = {
  "name": "Alice",
  "age": 22,
  "major": "Computer Science"
}

# Display data types
print(type(name))        # <class 'str'>
print(type(age))         # <class 'int'>
print(type(height))      # <class 'float'>
print(type(is_student))  # <class 'bool'>
print(type(fruits))      # <class 'list'>
print(type(person))      # <class 'dict'>

# Input from user
user_name = input("Enter your name: ")
user_age = input("Enter your age: ")

# Data type conversion
age_number = int(user_age)  # Convert string to integer

# Output with neat formatting
print(f"Hello {user_name}!")
print(f"You are {age_number} years old.")

# Mathematical operations
next_year = age_number + 1
print(f"Next year you will be {next_year} years old.")

# Output with different format
print("Name:", user_name)
print("Age:", age_number)
print("Age next year:", next_year)

# Basic mathematical operations
a = 10
b = 3

# Arithmetic operations
addition = a + b      # 13
subtraction = a - b   # 7
multiplication = a * b # 30
division = a / b      # 3.333...
floor_division = a // b # 3 (division result rounded down)
modulus = a % b       # 1 (remainder)
exponent = a ** b     # 1000 (10 to the power of 3)

print(f"{a} + {b} = {addition}")
print(f"{a} - {b} = {subtraction}")
print(f"{a} * {b} = {multiplication}")
print(f"{a} / {b} = {division}")
print(f"{a} // {b} = {floor_division}")
print(f"{a} % {b} = {modulus}")
print(f"{a} ** {b} = {exponent}")

# Operations with assignment
x = 5
x += 3  # x = x + 3, result is x = 8
x *= 2  # x = x * 2, result is x = 16
print(f"Current value of x: {x}")

# Simple calculator
print("=== SIMPLE CALCULATOR ===")

# Input from user
number1 = float(input("Enter first number: "))
operator = input("Enter operator (+, -, *, /): ")
number2 = float(input("Enter second number: "))

# Calculation process
if operator == "+":
  result = number1 + number2
elif operator == "-":
  result = number1 - number2
elif operator == "*":
  result = number1 * number2
elif operator == "/":
  if number2 != 0:
      result = number1 / number2
  else:
      print("Error: Cannot divide by zero!")
      result = None
else:
  print("Invalid operator!")
  result = None

# Output result
if result is not None:
  print(f"Result: {number1} {operator} {number2} = {result}")

# Temperature converter from Celsius to Fahrenheit and Kelvin
print("=== TEMPERATURE CONVERTER ===")

# Input temperature in Celsius
celsius = float(input("Enter temperature in Celsius: "))

if celsius < -273.15:
  raise ValueError("Temperature cannot be below absolute zero")

# Convert to Fahrenheit and Kelvin
fahrenheit = (celsius * 9/5) + 32
kelvin = celsius + 273.15

# Output conversion results
print(f"\nConversion results from {celsius}°C:")
print(f"Fahrenheit: {fahrenheit:.1f}°F")
print(f"Kelvin: {kelvin:.1f}K")

# Bonus: Additional information
if celsius < 0:
  print("This temperature is below water freezing point!")
elif celsius == 0:
  print("This temperature is water freezing point!")
elif celsius == 100:
  print("This temperature is water boiling point!")
elif celsius > 100:
  print("This temperature is above water boiling point!")

# Program to collect and display personal information
print("=== STUDENT PROFILE ===")

# Input information
name = input("Full name: ")
student_id = input("Student ID: ")
major = input("Major: ")
semester = int(input("Semester: "))
hobby = input("Favorite hobby: ")
current_year = int(input("Current year: "))

# Estimate using two semesters per academic year
entry_year = current_year - (semester - 1) // 2
estimated_graduation = entry_year + 4

# Display complete profile
print("\n" + "="*40)
print("STUDENT PROFILE")
print("="*40)
print(f"Name        : {name}")
print(f"Student ID  : {student_id}")
print(f"Major       : {major}")
print(f"Semester    : {semester}")
print(f"Hobby       : {hobby}")
print(f"Entry Year  : {entry_year}")
print(f"Est. Graduation: {estimated_graduation}")
print("="*40)

# Motivational message
if semester <= 2:
  print("Good luck at the beginning of your studies!")
elif semester <= 6:
  print("Keep up your learning spirit!")
else:
  print("Good luck finishing your studies!")