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Python If Statements

Control Flow Focus

Python If Statements

Conditionals determine what code runs. Learn idiomatic patterns, avoid nesting hell, and keep branches maintainable.

Practice guard clausesUse ternary expressions

Basic structure​

if score >= 90:
    grade = "A"
elif score >= 80:
    grade = "B"
else:
    grade = "Keep going"

Guard clauses​

if not user.active:
    raise PermissionError("Inactive user")

# continue with happy path

Reduces nesting and surfaces failure states early.

Nested conditionals​

Use sparingly. Prefer extraction into helper functions or dictionaries:

handlers = {
    "email": send_email,
    "sms": send_sms,
}
handler = handlers.get(channel)
if handler:
    handler(message)
else:
    raise ValueError("Unsupported channel")

Ternary operator​

status = "premium" if total > 100 else "standard"

Great for short expressions. Avoid chaining ternaries together; they harm readability.

Match-case vs if/elif​

Use match-case when pattern matching nested structures, but stick with if/elif for simple comparisons.

Next up in your learning path

Learn loops next

Pair conditionals with iteration.

Companion

Operators refresher

Solid operators make conditionals expressive.

Reference

Match-case deep dive

Use structural pattern matching for complex payloads.

Advanced

Frequently Asked Questions

Is there a switch statement in Python?

No traditional switch, but Python 3.10 introduced `match-case`, which provides pattern matching and covers most switch-style use cases.

How do I avoid deeply nested if statements?

Use guard clauses, helper functions, or dispatch tables (dict mapping keys to callables). When logic grows complex, consider state machines or strategy pattern.

Can I chain comparisons?

Yes. Python lets you write `0 < score <= 100`, which is equivalent to `(0 < score) and (score <= 100)` but more readable.