Master Python while Loops: Syntax, Flowcharts, and Advanced Tips

In Python programming, the while statement repeatedly executes a block of code while a given condition remains true, allowing repeated processing of identical tasks. while 判断条件：执行语句…… The condition can be any expression; any non‑zero or non‑empty value evaluates to true, and the loop terminates when the condition becomes false.

Execution flow is illustrated below:

Gif demonstration of Python while execution

Example

The output of the above code is shown below:

Two important commands, continue and break, can alter loop flow: continue skips the current iteration, while break exits the loop entirely. The condition can also be a constant true value, creating an infinite loop.

Infinite Loop

If the condition is always true, the loop runs indefinitely. Example:

Output of the infinite loop example:

Note: You can interrupt an infinite loop with CTRL+C.

Loop using else statement

In Python, while … else executes the else block when the loop condition becomes false.

Output of the above while … else example:

Simple statement group

Similar to an if statement, if the loop body contains only a single statement, you can place it on the same line as the while:

Note: You can interrupt the infinite loop with CTRL+C.