@@ -199,10 +199,8 @@ returns the list ``[0, 1, 2]``.
199199.. versionchanged :: 3.11
200200 Starred elements are now allowed in the expression list.
201201
202+
202203.. _try :
203- .. _except :
204- .. _except_star :
205- .. _finally :
206204
207205The :keyword: `!try ` statement
208206=============================
@@ -215,7 +213,7 @@ The :keyword:`!try` statement
215213 keyword: as
216214 single: : (colon); compound statement
217215
218- The :keyword: `try ` statement specifies exception handlers and/or cleanup code
216+ The :keyword: `! try ` statement specifies exception handlers and/or cleanup code
219217for a group of statements:
220218
221219.. productionlist :: python-grammar
@@ -231,40 +229,56 @@ for a group of statements:
231229 try3_stmt: "try" ":" `suite `
232230 : "finally" ":" `suite `
233231
232+ Additional information on exceptions can be found in section :ref: `exceptions `,
233+ and information on using the :keyword: `raise ` statement to generate exceptions
234+ may be found in section :ref: `raise `.
234235
235- The :keyword: `except ` clause(s) specify one or more exception handlers. When no
236+
237+ .. _except :
238+
239+ :keyword: `!except ` clause
240+ -------------------------
241+
242+ The :keyword: `!except ` clause(s) specify one or more exception handlers. When no
236243exception occurs in the :keyword: `try ` clause, no exception handler is executed.
237244When an exception occurs in the :keyword: `!try ` suite, a search for an exception
238- handler is started. This search inspects the except clauses in turn until one
239- is found that matches the exception. An expression-less except clause, if
240- present, must be last; it matches any exception. For an except clause with an
241- expression, that expression is evaluated, and the clause matches the exception
245+ handler is started. This search inspects the :keyword: `!except ` clauses in turn
246+ until one is found that matches the exception.
247+ An expression-less :keyword: `!except ` clause, if present, must be last;
248+ it matches any exception.
249+ For an :keyword: `!except ` clause with an expression,
250+ that expression is evaluated, and the clause matches the exception
242251if the resulting object is "compatible" with the exception. An object is
243252compatible with an exception if the object is the class or a
244253:term: `non-virtual base class <abstract base class> ` of the exception object,
245254or a tuple containing an item that is the class or a non-virtual base class
246255of the exception object.
247256
248- If no except clause matches the exception, the search for an exception handler
257+ If no :keyword: `!except ` clause matches the exception,
258+ the search for an exception handler
249259continues in the surrounding code and on the invocation stack. [# ]_
250260
251- If the evaluation of an expression in the header of an except clause raises an
252- exception, the original search for a handler is canceled and a search starts for
261+ If the evaluation of an expression
262+ in the header of an :keyword: `!except ` clause raises an exception,
263+ the original search for a handler is canceled and a search starts for
253264the new exception in the surrounding code and on the call stack (it is treated
254265as if the entire :keyword: `try ` statement raised the exception).
255266
256267.. index :: single: as; except clause
257268
258- When a matching except clause is found, the exception is assigned to the target
259- specified after the :keyword: `!as ` keyword in that except clause, if present, and
260- the except clause's suite is executed. All except clauses must have an
261- executable block. When the end of this block is reached, execution continues
262- normally after the entire try statement. (This means that if two nested
263- handlers exist for the same exception, and the exception occurs in the try
264- clause of the inner handler, the outer handler will not handle the exception.)
269+ When a matching :keyword: `!except ` clause is found,
270+ the exception is assigned to the target
271+ specified after the :keyword: `!as ` keyword in that :keyword: `!except ` clause,
272+ if present, and the :keyword: `!except ` clause's suite is executed.
273+ All :keyword: `!except ` clauses must have an executable block.
274+ When the end of this block is reached, execution continues
275+ normally after the entire :keyword: `try ` statement.
276+ (This means that if two nested handlers exist for the same exception,
277+ and the exception occurs in the :keyword: `!try ` clause of the inner handler,
278+ the outer handler will not handle the exception.)
265279
266280When an exception has been assigned using ``as target ``, it is cleared at the
267- end of the except clause. This is as if ::
281+ end of the :keyword: ` ! except` clause. This is as if ::
268282
269283 except E as N:
270284 foo
@@ -278,15 +292,17 @@ was translated to ::
278292 del N
279293
280294This means the exception must be assigned to a different name to be able to
281- refer to it after the except clause. Exceptions are cleared because with the
295+ refer to it after the :keyword: `!except ` clause.
296+ Exceptions are cleared because with the
282297traceback attached to them, they form a reference cycle with the stack frame,
283298keeping all locals in that frame alive until the next garbage collection occurs.
284299
285300.. index ::
286301 module: sys
287302 object: traceback
288303
289- Before an except clause's suite is executed, details about the exception are
304+ Before an :keyword: `!except ` clause's suite is executed,
305+ details about the exception are
290306stored in the :mod: `sys ` module and can be accessed via :func: `sys.exc_info `.
291307:func: `sys.exc_info ` returns a 3-tuple consisting of the exception class, the
292308exception instance and a traceback object (see section :ref: `types `) identifying
@@ -312,17 +328,24 @@ when leaving an exception handler::
312328 >>> print(sys.exc_info())
313329 (None, None, None)
314330
331+
315332.. index ::
316333 keyword: except_star
317334
318- The :keyword: `except*<except_star> ` clause(s) are used for handling
319- :exc: `ExceptionGroup `\ s. The exception type for matching is interpreted as in
335+ .. _except_star :
336+
337+ :keyword: `!except* ` clause
338+ --------------------------
339+
340+ The :keyword: `!except* ` clause(s) are used for handling
341+ :exc: `ExceptionGroup `\s . The exception type for matching is interpreted as in
320342the case of :keyword: `except `, but in the case of exception groups we can have
321343partial matches when the type matches some of the exceptions in the group.
322- This means that multiple except* clauses can execute, each handling part of
323- the exception group. Each clause executes once and handles an exception group
344+ This means that multiple :keyword: `!except* ` clauses can execute,
345+ each handling part of the exception group.
346+ Each clause executes once and handles an exception group
324347of all matching exceptions. Each exception in the group is handled by at most
325- one except* clause, the first that matches it. ::
348+ one :keyword: ` ! except*` clause, the first that matches it. ::
326349
327350 >>> try:
328351 ... raise ExceptionGroup("eg",
@@ -341,16 +364,16 @@ one except* clause, the first that matches it. ::
341364 | ValueError: 1
342365 +------------------------------------
343366
344- Any remaining exceptions that were not handled by any :keyword: `!except* `
345- clause are re-raised at the end, combined into an exception group along with
346- all exceptions that were raised from within :keyword: `!except* ` clauses.
367+ Any remaining exceptions that were not handled by any :keyword:`!except*`
368+ clause are re-raised at the end, combined into an exception group along with
369+ all exceptions that were raised from within :keyword:`!except*` clauses.
347370
348- An :keyword: `!except* ` clause must have a matching type,
349- and this type cannot be a subclass of :exc: `BaseExceptionGroup `.
350- It is not possible to mix :keyword: `except ` and :keyword: `!except* `
351- in the same :keyword: `try `.
352- :keyword: `break `, :keyword: `continue ` and :keyword: `return `
353- cannot appear in an :keyword: `!except* ` clause.
371+ An :keyword:`!except*` clause must have a matching type,
372+ and this type cannot be a subclass of :exc:`BaseExceptionGroup`.
373+ It is not possible to mix :keyword:`except` and :keyword:`!except*`
374+ in the same :keyword:`try`.
375+ :keyword:`break`, :keyword:`continue` and :keyword:`return`
376+ cannot appear in an :keyword:`!except*` clause.
354377
355378
356379.. index ::
@@ -359,17 +382,28 @@ cannot appear in an :keyword:`!except*` clause.
359382 statement: break
360383 statement: continue
361384
385+ .. _except_else :
386+
387+ :keyword: `!else ` clause
388+ -----------------------
389+
362390The optional :keyword: `!else ` clause is executed if the control flow leaves the
363391:keyword: `try ` suite, no exception was raised, and no :keyword: `return `,
364392:keyword: `continue `, or :keyword: `break ` statement was executed. Exceptions in
365393the :keyword: `!else ` clause are not handled by the preceding :keyword: `except `
366394clauses.
367395
396+
368397.. index :: keyword: finally
369398
370- If :keyword: `finally ` is present, it specifies a 'cleanup' handler. The
399+ .. _finally :
400+
401+ :keyword: `!finally ` clause
402+ --------------------------
403+
404+ If :keyword: `!finally ` is present, it specifies a 'cleanup' handler. The
371405:keyword: `try ` clause is executed, including any :keyword: `except ` and
372- :keyword: `! else ` clauses. If an exception occurs in any of the clauses and is
406+ :keyword: `else ` clauses. If an exception occurs in any of the clauses and is
373407not handled, the exception is temporarily saved. The :keyword: `!finally ` clause
374408is executed. If there is a saved exception it is re-raised at the end of the
375409:keyword: `!finally ` clause. If the :keyword: `!finally ` clause raises another
@@ -387,7 +421,7 @@ or :keyword:`continue` statement, the saved exception is discarded::
387421 42
388422
389423The exception information is not available to the program during execution of
390- the :keyword: `finally ` clause.
424+ the :keyword: `! finally ` clause.
391425
392426.. index ::
393427 statement: return
@@ -396,10 +430,10 @@ the :keyword:`finally` clause.
396430
397431When a :keyword: `return `, :keyword: `break ` or :keyword: `continue ` statement is
398432executed in the :keyword: `try ` suite of a :keyword: `!try `...\ :keyword: `!finally `
399- statement, the :keyword: `finally ` clause is also executed 'on the way out.'
433+ statement, the :keyword: `! finally ` clause is also executed 'on the way out.'
400434
401435The return value of a function is determined by the last :keyword: `return `
402- statement executed. Since the :keyword: `finally ` clause always executes, a
436+ statement executed. Since the :keyword: `! finally ` clause always executes, a
403437:keyword: `!return ` statement executed in the :keyword: `!finally ` clause will
404438always be the last one executed::
405439
@@ -412,13 +446,9 @@ always be the last one executed::
412446 >>> foo()
413447 'finally'
414448
415- Additional information on exceptions can be found in section :ref: `exceptions `,
416- and information on using the :keyword: `raise ` statement to generate exceptions
417- may be found in section :ref: `raise `.
418-
419449.. versionchanged :: 3.8
420450 Prior to Python 3.8, a :keyword: `continue ` statement was illegal in the
421- :keyword: `finally ` clause due to a problem with the implementation.
451+ :keyword: `! finally ` clause due to a problem with the implementation.
422452
423453
424454.. _with :
0 commit comments