diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst index e140f51f1dda78..138d87f892e891 100644 --- a/Doc/tutorial/controlflow.rst +++ b/Doc/tutorial/controlflow.rst @@ -4,8 +4,8 @@ More Control Flow Tools *********************** -Besides the :keyword:`while` statement just introduced, Python uses the usual -flow control statements known from other languages, with some twists. +As well as the :keyword:`while` statement just introduced, Python uses a few more +that we will encounter in this chapter. .. _tut-if: @@ -163,14 +163,21 @@ arguments. In chapter :ref:`tut-structures`, we will discuss in more detail abo :keyword:`!break` and :keyword:`!continue` Statements, and :keyword:`!else` Clauses on Loops ============================================================================================ -The :keyword:`break` statement, like in C, breaks out of the innermost enclosing +The :keyword:`break` statement breaks out of the innermost enclosing :keyword:`for` or :keyword:`while` loop. -Loop statements may have an :keyword:`!else` clause; it is executed when the loop -terminates through exhaustion of the iterable (with :keyword:`for`) or when the -condition becomes false (with :keyword:`while`), but not when the loop is -terminated by a :keyword:`break` statement. This is exemplified by the -following loop, which searches for prime numbers:: +A :keyword:`!for` or :keyword:`!while` loop can include an :keyword:`!else` clause. + +In a :keyword:`for` loop, the :keyword:`!else` clause is executed +after the loop reaches its final iteration. + +In a :keyword:`while` loop, it's executed after the loop's condition becomes false. + +In either kind of loop, the :keyword:`!else` clause is **not** executed +if the loop was terminated by a :keyword:`break`. + +This is exemplified in the following :keyword:`!for` loop, +which searches for prime numbers:: >>> for n in range(2, 10): ... for x in range(2, n):