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Diffstat (limited to 'Doc/reference')
| -rw-r--r-- | Doc/reference/expressions.rst | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index 41523cb..429fee4 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -320,7 +320,8 @@ Yield expressions yield_atom: "(" `yield_expression` ")" yield_expression: "yield" [`expression_list` | "from" `expression`] -The :keyword:`yield` expression is only used when defining a generator function, +The :keyword:`yield` expression is only used when defining a :term:`generator` +function, and can only be used in the body of a function definition. Using a :keyword:`yield` expression in a function definition is sufficient to cause that definition to create a generator function instead of a normal function. @@ -438,6 +439,12 @@ is already executing raises a :exc:`ValueError` exception. other exception, it is propagated to the caller. :meth:`close` does nothing if the generator has already exited due to an exception or normal exit. + +.. index:: single: yield; examples + +Examples +^^^^^^^^ + Here is a simple example that demonstrates the behavior of generators and generator functions:: @@ -465,6 +472,9 @@ generator functions:: >>> generator.close() Don't forget to clean up when 'close()' is called. +For examples using ``yield from``, see :ref:`pep-380` in "What's New in +Python." + .. seealso:: |