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merge 3.2

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Benjamin Peterson 2012-10-12 12:04:32 -04:00
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Doc/reference/expressions.rst
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@ -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.