Looping

Repeat a block of code while a condition holds.

File processing: read lines until end-of-file, Game development: poll for player input until a valid command is received, Data acquisition: wait for sensor readiness before proceeding

General Python programming, scripts, game loops, data processing pipelines.

while condition:

while ...:

condition: a boolean expression that determines loop continuation.

• break
• continue
• else clause
• increment/decrement variables
• sentinel values.

• for loop when iterating over known range
• recursion for tail recursion.

Failing to update condition leading to infinite loop; using assignment (=) instead of comparison (==) in condition; forgetting colon.

for loop (iterates over iterables); do-while loop (not in Python) ensures at least one execution.

Coming from languages with do-while syntax (e.g., C, Java): may expect loop to run at least once; in Python while may zero iterations.

• for loop
• loop control statements (break
• continue)
• recursion

The condition is evaluated before each iteration; if false initially, body never runs. Use while True with break for infinite loops needing exit condition inside.

Enables repeated execution until a condition changes, essential for polling and iterative algorithms.

Think 'while the light is green, keep driving'.

Common pitfalls include forgetting to update the condition leading to infinite loops, using assignment (=) instead of comparison (==) in the condition, and omitting the colon after the condition.

while True: ... break