diff options
Diffstat (limited to 'Lib/gzip.py')
| -rw-r--r-- | Lib/gzip.py | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/Lib/gzip.py b/Lib/gzip.py index 93dda4edd4..85c3e150d9 100644 --- a/Lib/gzip.py +++ b/Lib/gzip.py @@ -93,6 +93,9 @@ class GzipFile(io.BufferedIOBase): """The GzipFile class simulates most of the methods of a file object with the exception of the readinto() and truncate() methods. + This class only supports opening files in binary mode. If you need to open a + compressed file in text mode, wrap your GzipFile with an io.TextIOWrapper. + """ myfileobj = None @@ -119,8 +122,8 @@ class GzipFile(io.BufferedIOBase): The mode argument can be any of 'r', 'rb', 'a', 'ab', 'w', or 'wb', depending on whether the file will be read or written. The default is the mode of fileobj if discernible; otherwise, the default is 'rb'. - Be aware that only the 'rb', 'ab', and 'wb' values should be used - for cross-platform portability. + A mode of 'r' is equivalent to one of 'rb', and similarly for 'w' and + 'wb', and 'a' and 'ab'. The compresslevel argument is an integer from 1 to 9 controlling the level of compression; 1 is fastest and produces the least compression, @@ -137,8 +140,8 @@ class GzipFile(io.BufferedIOBase): """ - # guarantee the file is opened in binary mode on platforms - # that care about that sort of thing + if mode and ('t' in mode or 'U' in mode): + raise ValueError("Invalid mode: {!r}".format(mode)) if mode and 'b' not in mode: mode += 'b' if fileobj is None: @@ -149,10 +152,9 @@ class GzipFile(io.BufferedIOBase): else: filename = '' if mode is None: - if hasattr(fileobj, 'mode'): mode = fileobj.mode - else: mode = 'rb' + mode = getattr(fileobj, 'mode', 'rb') - if mode[0:1] == 'r': + if mode.startswith('r'): self.mode = READ # Set flag indicating start of a new member self._new_member = True @@ -167,7 +169,7 @@ class GzipFile(io.BufferedIOBase): self.min_readsize = 100 fileobj = _PaddedFile(fileobj) - elif mode[0:1] == 'w' or mode[0:1] == 'a': + elif mode.startswith(('w', 'a')): self.mode = WRITE self._init_write(filename) self.compress = zlib.compressobj(compresslevel, @@ -176,7 +178,7 @@ class GzipFile(io.BufferedIOBase): zlib.DEF_MEM_LEVEL, 0) else: - raise IOError("Mode " + mode + " not supported") + raise ValueError("Invalid mode: {!r}".format(mode)) self.fileobj = fileobj self.offset = 0 |