cpython: 22247b7d17fa (original) (raw)

Mercurial > cpython

changeset 86403:22247b7d17fa

Close #19266: contextlib.ignore -> contextlib.suppress Patch by Zero Piraeus. [#19266]

Nick Coghlan ncoghlan@gmail.com
date	Thu, 17 Oct 2013 23:40:57 +1000
parents	5cc9cbfb5cff
children	9853d3a20849
files	Doc/library/contextlib.rst Doc/whatsnew/3.4.rst Lib/contextlib.py Lib/test/test_contextlib.py Misc/ACKS Misc/NEWS
diffstat	6 files changed, 58 insertions(+), 39 deletions(-)[+] [-] Doc/library/contextlib.rst 26 Doc/whatsnew/3.4.rst 13 Lib/contextlib.py 8 Lib/test/test_contextlib.py 44 Misc/ACKS 1 Misc/NEWS 5

line wrap: on

line diff

--- a/Doc/library/contextlib.rst +++ b/Doc/library/contextlib.rst @@ -95,22 +95,27 @@ Functions and classes provided: page.close() will be called when the :keyword:with block is exited. -.. function:: ignore(*exceptions) +.. function:: suppress(*exceptions)

Return a context manager that ignores the specified exceptions if they
occur in the body of a with-statement.

Return a context manager that suppresses any of the specified exceptions
if they occur in the body of a with statement and then resumes execution
with the first statement following the end of the with statement.

As with any other mechanism that completely suppresses exceptions, it
should only be used to cover very specific errors where silently
ignoring the exception is known to be the right thing to do.

As with any other mechanism that completely suppresses exceptions, this
context manager should be used only to cover very specific errors where
silently continuing with program execution is known to be the right
thing to do. For example::

  from contextlib import ignore[](#l1.26)

  from contextlib import suppress[](#l1.27)

  with ignore(FileNotFoundError):[](#l1.29)

  with suppress(FileNotFoundError):[](#l1.30)
      os.remove('somefile.tmp')[](#l1.31)

  with suppress(FileNotFoundError):[](#l1.33)

      os.remove('someotherfile.tmp')[](#l1.34)

+ This code is equivalent to:: try: @@ -118,6 +123,11 @@ Functions and classes provided: except FileNotFoundError: pass

```
  try:[](#l1.43)
```

      os.remove('someotherfile.tmp')[](#l1.44)

```
  except FileNotFoundError:[](#l1.45)
```
```
      pass[](#l1.46)
```

+ .. versionadded:: 3.4

--- a/Doc/whatsnew/3.4.rst +++ b/Doc/whatsnew/3.4.rst @@ -221,14 +221,17 @@ results should be less than 1% and may b contextlib ---------- -The new :class:contextlib.ignore context manager helps to clarify the -intent of code that deliberately ignores failures from a particular -operation. +The new :class:contextlib.suppress context manager helps to clarify the +intent of code that deliberately suppresses exceptions from a single +statement. (Contributed by Raymond Hettinger in :issue:15806 and +Zero Piraeus in :issue:19266) + The new :class:contextlib.redirect_stdio context manager makes it easier for utility scripts to handle inflexible APIs that don't provide any options to retrieve their output as a string or direct it to somewhere -other than :data:sys.stdout. +other than :data:sys.stdout. (Contribute by Raymond Hettinger in +:issue:15805) dis @@ -283,7 +286,7 @@ result: a bytes object containing the f A pair of new subclasses of :class:~email.message.Message have been added, along with a new sub-module, :mod:~email.contentmanager. All documentation is currently in the new module, which is being added as part of the new -:term:provisional <provosional package> email API. These classes provide a +:term:provisional <provisional package> email API. These classes provide a number of new methods that make extracting content from and inserting content into email messages much easier. See the :mod:~email.contentmanager documentation for details.

--- a/Lib/contextlib.py +++ b/Lib/contextlib.py @@ -5,7 +5,7 @@ from collections import deque from functools import wraps all = ["contextmanager", "closing", "ContextDecorator", "ExitStack",

      "ignore", "redirect_stdout"][](#l3.7)

      "redirect_stdout", "suppress"][](#l3.8)

class ContextDecorator(object): @@ -179,10 +179,10 @@ class redirect_stdout: sys.stdout = self.old_target @contextmanager -def ignore(*exceptions):

"""Context manager to ignore specified exceptions

+def suppress(*exceptions):

"""Context manager to suppress specified exceptions

```
    with ignore(OSError):[](#l3.21)
```

    with suppress(OSError):[](#l3.22)
        os.remove(somefile)[](#l3.23)

"""

--- a/Lib/test/test_contextlib.py +++ b/Lib/test/test_contextlib.py @@ -632,28 +632,6 @@ class TestExitStack(unittest.TestCase): stack.push(cm) self.assertIs(stack._exit_callbacks[-1], cm) -class TestIgnore(unittest.TestCase): -

def test_no_exception(self):

```
   with ignore(ValueError):[](#l4.11)
```

       self.assertEqual(pow(2, 5), 32)[](#l4.12)

def test_exact_exception(self):

```
   with ignore(TypeError):[](#l4.16)
```
```
       len(5)[](#l4.17)
```

def test_multiple_exception_args(self):

   with ignore(ZeroDivisionError, TypeError):[](#l4.21)

```
       len(5)[](#l4.22)
```

def test_exception_hierarchy(self):

```
   with ignore(LookupError):[](#l4.26)
```
```
       'Hello'[50][](#l4.27)
```

- class TestRedirectStdout(unittest.TestCase): def test_redirect_to_string_io(self): @@ -663,5 +641,27 @@ class TestRedirectStdout(unittest.TestCa s = f.getvalue() self.assertIn('pow', s) +class TestSuppress(unittest.TestCase): +

def test_no_exception(self):

```
   with suppress(ValueError):[](#l4.40)
```

       self.assertEqual(pow(2, 5), 32)[](#l4.41)

def test_exact_exception(self):

```
   with suppress(TypeError):[](#l4.45)
```
```
       len(5)[](#l4.46)
```

def test_multiple_exception_args(self):

   with suppress(ZeroDivisionError, TypeError):[](#l4.50)

```
       len(5)[](#l4.51)
```

def test_exception_hierarchy(self):

   with suppress(LookupError):[](#l4.55)

```
       'Hello'[50][](#l4.56)
```

+ if name == "main": unittest.main()

--- a/Misc/ACKS +++ b/Misc/ACKS @@ -1003,6 +1003,7 @@ Anand B. Pillai François Pinard Tom Pinckney Zach Pincus +Zero Piraeus Michael Piotrowski Antoine Pitrou Jean-François Piéronne

--- a/Misc/NEWS +++ b/Misc/NEWS @@ -42,6 +42,11 @@ Core and Builtins Library ------- +- Issue #19266: Rename the new-in-3.4 contextlib.ignore context manager

to contextlib.suppress in order to be more consistent with existing
descriptions of that operation elsewhere in the language and standard
library documentation (Patch by Zero Piraeus) +

Issue #18891: Completed the new email package (provisional) API additions by adding new classes EmailMessage, MIMEPart, and ContentManager.