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| author | Antoine Pitrou <solipsis@pitrou.net> | 2009-12-19 21:08:31 (GMT) |
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| committer | Antoine Pitrou <solipsis@pitrou.net> | 2009-12-19 21:08:31 (GMT) |
| commit | d5587bc4745f9d0b1dfdf7c93947f5b197a37176 (patch) | |
| tree | 23011af2790bf7835e431ed21c55fcbeb305a01d /Lib/_pyio.py | |
| parent | 1d523e1ae18d5a021c11beaca4ba664e0a6786e9 (diff) | |
| download | cpython-d5587bc4745f9d0b1dfdf7c93947f5b197a37176.zip cpython-d5587bc4745f9d0b1dfdf7c93947f5b197a37176.tar.gz cpython-d5587bc4745f9d0b1dfdf7c93947f5b197a37176.tar.bz2 | |
Merged revisions 76896,76898 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
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r76896 | antoine.pitrou | 2009-12-19 22:01:10 +0100 (sam., 19 déc. 2009) | 3 lines
Issue #7545: improve documentation of the `buffering` argument in io.open().
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r76898 | antoine.pitrou | 2009-12-19 22:06:36 +0100 (sam., 19 déc. 2009) | 3 lines
Remove superfetatory paragraph (left there by mistake).
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Diffstat (limited to 'Lib/_pyio.py')
| -rw-r--r-- | Lib/_pyio.py | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/Lib/_pyio.py b/Lib/_pyio.py index 04aed8d..a4beb2b 100644 --- a/Lib/_pyio.py +++ b/Lib/_pyio.py @@ -82,10 +82,20 @@ def open(file: (str, bytes), mode: str = "r", buffering: int = None, returned as strings, the bytes having been first decoded using a platform-dependent encoding or using the specified encoding if given. - buffering is an optional integer used to set the buffering policy. By - default full buffering is on. Pass 0 to switch buffering off (only - allowed in binary mode), 1 to set line buffering, and an integer > 1 - for full buffering. + buffering is an optional integer used to set the buffering policy. + Pass 0 to switch buffering off (only allowed in binary mode), 1 to select + line buffering (only usable in text mode), and an integer > 1 to indicate + the size of a fixed-size chunk buffer. When no buffering argument is + given, the default buffering policy works as follows: + + * Binary files are buffered in fixed-size chunks; the size of the buffer + is chosen using a heuristic trying to determine the underlying device's + "block size" and falling back on `io.DEFAULT_BUFFER_SIZE`. + On many systems, the buffer will typically be 4096 or 8192 bytes long. + + * "Interactive" text files (files for which isatty() returns True) + use line buffering. Other text files use the policy described above + for binary files. encoding is the name of the encoding used to decode or encode the file. This should only be used in text mode. The default encoding is |