Python Control Flow Cheat Sheet: if, for, while, match

Q: What is the difference between break and continue in Python?

`break` ends the whole loop immediately, while `continue` skips the rest of the current iteration and moves to the next one.

Q: Does Python have a switch statement?

Python 3.10 added the `match` statement, which works like a switch and also matches patterns such as lists and dicts. Before that, people used `if`/`elif` chains or dictionaries.

Q: What does the else on a Python for loop do?

The `else` block runs only when the loop finishes without hitting `break`. It is handy for search loops that need a "not found" branch.

By Yogesh Sharma (LinkedIn) · Every code example is run and checked on Python 3.13 (how we test) · Last updated 21 Oct 2026

Short answer

Python control flow uses if/elif/else to choose, for and while to repeat, break and continue to steer loops, and match (Python 3.10+) to branch on the shape of a value.

Control flow decides which lines run and how often. The tables here cover decisions, truthiness, loops, loop control and pattern matching, with the real output of every line that can be run on one line. Longer blocks are described in words.

For the full explanations see if...else, for loops and while loops.

Python if, elif and else cheat sheet

Assume `age = 20`, `has_id = True`, `name = ""` and `value = None`. Conditions evaluate to `True` or `False`, and `if` runs its block on `True`.
Task	Code	Result
Basic if / else as one line	`"pass" if 72 >= 40 else "fail"`	`'pass'`
Grade with elif chain	`"A" if 91 >= 90 else "B" if 91 >= 80 else "C"`	`'A'`
Greater than or equal	`10 >= 10`	`True`
Not equal	`"a" != "b"`	`True`
Both conditions (and)	`age >= 18 and has_id`	`True`
Either condition (or)	`age < 13 or age > 65`	`False`
Negate (not)	`not has_id`	`False`
Chained range check	`18 <= age < 30`	`True`
Default with or	`name or "guest"`	`'guest'`
Check None correctly	`value is None`	`True`
Even or odd	`"even" if 7 % 2 == 0 else "odd"`	`'odd'`
Leap year test	`(2024 % 4 == 0 and 2024 % 100 != 0) or 2024 % 400 == 0`	`True`

Python truthy and falsy values cheat sheet

Task	Code	Result
Zero is falsy	`bool(0)`	`False`
Non-zero number is truthy	`bool(-3)`	`True`
Empty string is falsy	`bool("")`	`False`
Text "False" is truthy	`bool("False")`	`True`
Empty list is falsy	`bool([])`	`False`
Empty dict is falsy	`bool({})`	`False`
None is falsy	`bool(None)`	`False`
and returns the first falsy value	`3 and 0 and 5`	`0`
or returns the first truthy value	`0 or [] or "x"`	`'x'`
not always returns a bool	`not "hello"`	`False`
Compare with == not truthiness	`0 == False`	`True`
any and all on lists	`any([0, "", 5]), all([1, "a"])`	`(True, True)`

Python for loop and range cheat sheet

Task	Code	Result
Count 0 to 4	`list(range(5))`	`[0, 1, 2, 3, 4]`
Count 1 to 5	`list(range(1, 6))`	`[1, 2, 3, 4, 5]`
Step by 2	`list(range(0, 10, 2))`	`[0, 2, 4, 6, 8]`
Count down	`list(range(5, 0, -1))`	`[5, 4, 3, 2, 1]`
Loop over a list	`for fruit in ["apple", "kiwi"]: print(fruit)`	`apple, kiwi`
Loop over a string	`for ch in "abc": print(ch, end="")`	`abc`
Index and value	`list(enumerate(["a", "b"]))`	`[(0, 'a'), (1, 'b')]`
Two lists together	`list(zip([1, 2, 3], ["x", "y"]))`	`[(1, 'x'), (2, 'y')]`
Sum in a loop	`for n in [4, 5]: t += n`	`9`
Reverse a loop	`list(reversed([1, 2, 3]))`	`[3, 2, 1]`
Multiplication table row	`[3 * i for i in range(1, 6)]`	`[3, 6, 9, 12, 15]`
Nested loops	`[(r, c) for r in range(2) for c in range(2)]`	`[(0, 0), (0, 1), (1, 0), (1, 1)]`

Python while loop, break and continue cheat sheet

Task	Code	Result
Basic while loop	`while i < 4: total += i; i += 1`	`6`
break exits the loop	`for n in [1, 2, 3, 4]: print(n); break`	`1`
continue skips an item	`[n for n in range(5) if n != 2]`	`[0, 1, 3, 4]`
Find first match	`next(n for n in [3, 8, 5, 12] if n > 6)`	`8`
Default when nothing matches	`next((n for n in [1, 2] if n > 6), None)`	`None`
break vs continue vs pass	`pass`	`pass` does nothing, a placeholder
Loop with else	`else: # runs if no break`	the `else` of a loop runs only when the loop was not stopped by `break`
Infinite loop with exit	`while True: break`	`no output`
Accumulate until a limit	`while t < 10: t += 4`	`12`
Countdown	`[n for n in range(3, 0, -1)]`	`[3, 2, 1]`
Digits of a number	`[int(d) for d in str(1234)]`	`[1, 2, 3, 4]`
Sum of digits	`sum(int(d) for d in str(1234))`	`10`

Python match statement and conditional patterns

Task	Code	Result
Match a value	`match code: case 200: ...`	runs the first `case` whose value equals `code`
Several values in one case	`case 401 \| 403:`	matches either value
Wildcard default	`case _:`	matches anything, so put it last
Match a sequence	`case [x, y]:`	matches a two-item list and binds `x`, `y`
Match a dict shape	`case {"kind": k}:`	matches any dict that has a `kind` key
Guard with if	`case n if n > 5:`	matches only when the guard is true
Lookup table alternative	`{"a": 1, "b": 2}.get("b", 0)`	`2`
Ternary for two outcomes	`"yes" if 3 > 2 else "no"`	`'yes'`
Nested if flattened with and	`(5 > 1 and 5 < 9)`	`True`
Membership instead of many ors	`5 in (1, 5, 9)`	`True`

Python common control flow programs

Task	Code	Result
FizzBuzz for 15	`"FizzBuzz" if 15 % 15 == 0 else 15`	`'FizzBuzz'`
Is a number prime?	`n > 1 and all(n % d for d in range(2, int(n ** 0.5) + 1))`	`True`
Factorial	`math.factorial(5)`	`120`
Fibonacci step	`a, b = b, a + b`	from `0, 1` this yields 0, 1, 1, 2, 3, 5, 8, 13
GCD	`math.gcd(48, 18)`	`6`
Armstrong check for 153	`sum(int(d) ** 3 for d in "153") == 153`	`True`
Star pattern row	`"" 3`	`'***'`
Linear search	`[4, 7, 9].index(7)`	`1`
Largest of three	`max(3, 9, 4)`	`9`
Average	`sum([4, 6, 8]) / 3`	`6.0`

Examples you can run

Press Run, then edit the code and run it again.

Loop with if, continue and break

Print odd numbers and stop at the first number above 7.

Loop with if, continue and break

for n in range(1, 12):
    if n % 2 == 0:
        continue
    if n > 7:
        break
    print(n)

Expected output1
3
5
7

Classify values with match

match picks the first case that fits; _ is the default.

Classify values with match

def kind(code):
    match code:
        case 200 | 201:
            return "success"
        case 404:
            return "missing"
        case _:
            return "other"

print(kind(201), kind(404), kind(500))

Expected outputsuccess missing other

Python Control Flow Cheat Sheet: if, for, while, match: questions people ask

What is the difference between break and continue in Python?

break ends the whole loop immediately, while continue skips the rest of the current iteration and moves to the next one.

Does Python have a switch statement?

Python 3.10 added the match statement, which works like a switch and also matches patterns such as lists and dicts. Before that, people used if/elif chains or dictionaries.

What does the else on a Python for loop do?

The else block runs only when the loop finishes without hitting break. It is handy for search loops that need a "not found" branch.

Keep learning

Step-by-step lessons:
Python if, elif and else Python for Loops Python while Loops

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