Ch1. Python Fundamentals — Setup, Syntax & Your First Program

Why Python?

Python is the world’s most popular programming language (TIOBE Index #1, 2024).

Why Python wins:

• Readable, English-like syntax that’s beginner-friendly
• Massive library ecosystem (data science, AI/ML, web, automation)
• Fast development cycle (interpreted language)
• The de facto standard for data science and AI/ML

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Installation

Option 1: Anaconda (recommended for beginners)

1. Download Anaconda at anaconda.com
2. Launch Jupyter Notebook after installation
3. Comes with all major data science libraries pre-installed

Option 2: Python + VS Code

1. Download Python 3.x from python.org
2. Install VS Code + Python extension
3. Verify with python --version in terminal

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Basic Data Types

# Integer
age = 25
count = -3

# Float
pi = 3.14159
temperature = -2.5

# String
name = "Alice"
greeting = 'Hello, World!'

# Boolean
is_student = True
is_raining = False

# Check types
print(type(age))        # <class 'int'>
print(type(pi))         # <class 'float'>
print(type(name))       # <class 'str'>

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Operators

# Arithmetic
print(10 + 3)   # 13
print(10 - 3)   # 7
print(10 * 3)   # 30
print(10 / 3)   # 3.333...
print(10 // 3)  # 3  (floor division)
print(10 % 3)   # 1  (modulo)
print(10 ** 2)  # 100 (exponentiation)

# Comparison
print(5 > 3)    # True
print(5 == 5)   # True
print(5 != 4)   # True

# Logical
print(True and False)  # False
print(True or False)   # True
print(not True)        # False

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Conditionals

score = 85

if score >= 90:
    print("A")
elif score >= 80:
    print("B")
elif score >= 70:
    print("C")
else:
    print("F")
# Output: B

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Loops

# for loop
for i in range(5):
    print(i, end=" ")  # 0 1 2 3 4

# while loop
count = 0
while count < 3:
    print(f"Count: {count}")
    count += 1

# Iterate over a list
fruits = ["apple", "banana", "cherry"]
for fruit in fruits:
    print(fruit)

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First Program: Temperature Converter

def celsius_to_fahrenheit(celsius):
    fahrenheit = (celsius * 9/5) + 32
    return fahrenheit

temp_c = float(input("Enter temperature in Celsius: "))
temp_f = celsius_to_fahrenheit(temp_c)
print(f"{temp_c}°C = {temp_f:.1f}°F")

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Chapter 2 Preview

Next: Python Data Structures — lists, dictionaries, tuples, sets, and list comprehensions.