02_data_types.md

2. Data Types in Python

In Python, data types determine what kind of value a variable holds. Understanding data types is essential because they define how data behaves and how you can interact with it.

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🔢 Basic Data Types

Type	Description	Example
int	Integer (whole number)	x = 10
float	Decimal number	pi = 3.14
str	String (text)	name = "Yunus"
bool	Boolean (True or False)	is_active = True

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🧠 Examples

age = 30                  # int
price = 19.99            # float
first_name = "Yunus"      # str
is_logged_in = False     # bool

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📏 Checking Types

You can use the type() function to check the type of a value:

print(type(age))         # <class 'int'>
print(type(price))       # <class 'float'>
print(type(first_name))  # <class 'str'>
print(type(is_logged_in)) # <class 'bool'>

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🔁 Type Conversion (Casting)

You can convert values from one type to another:

x = 5          # int
x_str = str(x) # "5"

price = "19.99"
price_float = float(price)

Built-in functions:

• int() → to integer
• float() → to float
• str() → to string
• bool() → to boolean

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🧪 Practice: Type Checking & Conversion

user_input = "42"
number = int(user_input)

print("Value:", number)
print("Type:", type(number))

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⚠️ Common Pitfalls

x = "5"
y = 2
result = x + y  # ❌ TypeError: cannot concatenate str and int

✅ Fix:

result = int(x) + y

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✅ Summary

• Python has dynamic typing: variables can hold different types
• Use type() to inspect data types
• Use casting functions to convert between types
• Common types: int, float, str, bool

Understanding data types is crucial for writing bug-free, efficient Python code. 🧠🐍