Executing code until a condition is met using while loops
A very common use case for command-line programs is to keep asking a user for more information until a certain condition is met. With our current set of tools, this would be difficult. We know how to ask a user for information (using the input()
function) and we know how to check information (using if
clauses), but how could we keep executing a piece of code until a condition (that is, the correct input from a user) is met? We could use a for
loop with an extremely high number, but this number would also eventually come to an end.
To address this, Python includes a while
loop. while
loops are essentially a combination of a loop and an if
clause that allow us to execute a piece of code until a condition is met.
In this recipe, you'll see how to use a while
loop to keep asking a user for more IP addresses that we will add to a list. Once the user is satisfied with the addresses they have added, we will terminate the...