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| -rw-r--r-- | Doc/library/functions.rst | 30 | ||||
| -rw-r--r-- | Doc/library/io.rst | 3 | ||||
| -rw-r--r-- | Misc/ACKS | 1 |
3 files changed, 34 insertions, 0 deletions
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst index 0fb48f4..5df7b67 100644 --- a/Doc/library/functions.rst +++ b/Doc/library/functions.rst @@ -935,6 +935,36 @@ are always available. They are listed here in alphabetical order. :mod:`os.open` as *opener* results in functionality similar to passing ``None``). + The following example is an alternative implementation for opening files + for exclusive writing. If we did not have support for the ``'x'`` mode, + we could implement it with this opener:: + + >>> import os + >>> def open_exclusive(path, mode): + ... return os.open(path, mode | os.O_CREAT | os.O_EXCL) + ... + >>> filename = 'spam.txt' + >>> fp = open(filename, 'w', opener=open_exclusive) + >>> fp2 = open(filename, 'w', opener=open_exclusive) + Traceback (most recent call last): + ... + FileExistsError: [Errno 17] File exists: 'spam.txt' + + This other example uses the :ref:`dir_fd` parameter of the + :func:`os.open` function to open a file relative to a given directory:: + + >>> import os + >>> def open_relative(dirname): + ... dir_fd = os.open(dirname, os.O_RDONLY) + ... def opener(path, flags): + ... return os.open(path, flags, dir_fd=dir_fd) + ... return opener + ... + >>> opener = open_relative('somedir') + >>> with open('spamspam.txt', 'w', opener=opener) as f: + ... print('This will be written to somedir/spamspam.txt', file=f) + ... + .. versionchanged:: 3.3 The *opener* parameter was added. The ``'x'`` mode was added. diff --git a/Doc/library/io.rst b/Doc/library/io.rst index e83e55c..44e663d 100644 --- a/Doc/library/io.rst +++ b/Doc/library/io.rst @@ -498,6 +498,9 @@ Raw File I/O :mod:`os.open` as *opener* results in functionality similar to passing ``None``). + See the :func:`open` built-in function for examples on using the *opener* + parameter. + .. versionchanged:: 3.3 The *opener* parameter was added. The ``'x'`` mode was added. @@ -929,6 +929,7 @@ Michael Pomraning Iustin Pop Claudiu Popa John Popplewell +Guillaume Pratte Amrit Prem Paul Prescod Donovan Preston |