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Diffstat (limited to 'Doc/reference/expressions.rst')
| -rw-r--r-- | Doc/reference/expressions.rst | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst index 364135a..41523cb 100644 --- a/Doc/reference/expressions.rst +++ b/Doc/reference/expressions.rst @@ -294,13 +294,13 @@ for comprehensions, except that it is enclosed in parentheses instead of brackets or curly braces. Variables used in the generator expression are evaluated lazily when the -:meth:`__next__` method is called for generator object (in the same fashion as -normal generators). However, the leftmost :keyword:`for` clause is immediately -evaluated, so that an error produced by it can be seen before any other possible -error in the code that handles the generator expression. Subsequent -:keyword:`for` clauses cannot be evaluated immediately since they may depend on -the previous :keyword:`for` loop. For example: ``(x*y for x in range(10) for y -in bar(x))``. +:meth:`~generator.__next__` method is called for generator object (in the same +fashion as normal generators). However, the leftmost :keyword:`for` clause is +immediately evaluated, so that an error produced by it can be seen before any +other possible error in the code that handles the generator expression. +Subsequent :keyword:`for` clauses cannot be evaluated immediately since they +may depend on the previous :keyword:`for` loop. For example: ``(x*y for x in +range(10) for y in bar(x))``. The parentheses can be omitted on calls with only one argument. See section :ref:`calls` for the detail. @@ -394,10 +394,11 @@ is already executing raises a :exc:`ValueError` exception. Starts the execution of a generator function or resumes it at the last executed :keyword:`yield` expression. When a generator function is resumed - with a :meth:`__next__` method, the current :keyword:`yield` expression - always evaluates to :const:`None`. The execution then continues to the next - :keyword:`yield` expression, where the generator is suspended again, and the - value of the :token:`expression_list` is returned to :meth:`next`'s caller. + with a :meth:`~generator.__next__` method, the current :keyword:`yield` + expression always evaluates to :const:`None`. The execution then continues + to the next :keyword:`yield` expression, where the generator is suspended + again, and the value of the :token:`expression_list` is returned to + :meth:`next`'s caller. If the generator exits without yielding another value, a :exc:`StopIteration` exception is raised. |