Debugging with pdb & IDE Debugger

# Using pdb (Python Debugger)
# import pdb; pdb.set_trace()  # old way
# breakpoint()                  # Python 3.7+ (preferred!)

# pdb commands:
# n  — next line
# s  — step into function
# c  — continue execution
# p  — print variable value
# l  — list source code
# q  — quit debugger
# h  — help

# Demo: debugging a function
def calculate_average(numbers):
    """Bug: doesn't handle empty list."""
    # breakpoint()  # uncomment to debug
    if not numbers:
        return 0
    total = sum(numbers)
    count = len(numbers)
    average = total / count
    return average

# Test cases
print("=== Debugging Demo ===")
print(f"Average [1,2,3]: {calculate_average([1, 2, 3])}")
print(f"Average []: {calculate_average([])}")
print(f"Average [10]: {calculate_average([10])}")

# VS Code debugging tips:
print("\n=== VS Code Debug Tips ===")
print("1. Click left of line number → set breakpoint")
print("2. F5 → start debugging")
print("3. F10 → step over")
print("4. F11 → step into")
print("5. Shift+F11 → step out")
print("6. Watch variables in sidebar")
print("7. Use Debug Console for expressions")