The GzipFile class is accessible via the webob.util.safegzip module.
Constructor for the GzipFile class.
At least one of fileobj and filename must be given a non-trivial value.
The new class instance is based on fileobj, which can be a regular file, a StringIO object, or any other object which simulates a file. It defaults to None, in which case filename is opened to provide a file object.
When fileobj is not None, the filename argument is only used to be included in the gzip file header, which may includes the original filename of the uncompressed file. It defaults to the filename of fileobj, if discernible; otherwise, it defaults to the empty string, and in this case the original filename is not included in the header.
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.
The compresslevel argument is an integer from 1 to 9 controlling the level of compression; 1 is fastest and produces the least compression, and 9 is slowest and produces the most compression. The default is 9.
See the source for more information.