我想使用python压缩一些可能达到99 GB左右的文件.请问使用zipfile库最有效的方法是什么.这是我的示例代码
with gcs.open(zip_file_name, 'w', content_type=b'application/zip') as f:
with zipfile.ZipFile(f, 'w') as z:
for file in files:
is_owner = (is_page_allowed_to_visitor(page, visitor) or (file.owner_id == visitor.id) )
if is_owner:
file.show = True
elif file.available_from:
if file.available_from > datetime.now():
file.show = False
elif file.available_to:
if file.available_to < datetime.now():
file.show = False
else:
file.show = True
if file.show:
file_name = "/%s/%s" % (gcs_store.get_bucket_name(), file.gcs_name)
gcs_reader = gcs.open(file_name, 'r')
z.writestr('%s-%s' %(file.created_on, file.name), gcs_reader.read() )
gcs_reader.close()
f.close() #closing zip file
有些要点需要注意:
1)我使用谷歌应用引擎来托管文件,所以我不能使用zipfile.write()方法.我只能以字节为单位获取文件内容.
提前致谢
解决方法:
我在zipfile库中添加了一个新方法.这个增强的zipfile库是开源的,可以在github上找到(EnhancedZipFile).我添加了一个新方法,其灵感来自zipfile.write()方法和zipfile.writestr()方法
def writebuffered(self, zinfo_or_arcname, file_pointer, file_size, compress_type=None):
if not isinstance(zinfo_or_arcname, ZipInfo):
zinfo = ZipInfo(filename=zinfo_or_arcname,
date_time=time.localtime(time.time())[:6])
zinfo.compress_type = self.compression
if zinfo.filename[-1] == '/':
zinfo.external_attr = 0o40775 << 16 # drwxrwxr-x
zinfo.external_attr |= 0x10 # MS-DOS directory flag
else:
zinfo.external_attr = 0o600 << 16 # ?rw-------
else:
zinfo = zinfo_or_arcname
zinfo.file_size = file_size # Uncompressed size
zinfo.header_offset = self.fp.tell() # Start of header bytes
self._writecheck(zinfo)
self._didModify = True
fp = file_pointer
# Must overwrite CRC and sizes with correct data later
zinfo.CRC = CRC = 0
zinfo.compress_size = compress_size = 0
# Compressed size can be larger than uncompressed size
zip64 = self._allowZip64 and \
zinfo.file_size * 1.05 > ZIP64_LIMIT
self.fp.write(zinfo.FileHeader(zip64))
if zinfo.compress_type == ZIP_DEFLATED:
cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
zlib.DEFLATED, -15)
else:
cmpr = None
file_size = 0
while 1:
buf = fp.read(1024 * 8)
if not buf:
break
file_size = file_size + len(buf)
CRC = crc32(buf, CRC) & 0xffffffff
if cmpr:
buf = cmpr.compress(buf)
compress_size = compress_size + len(buf)
self.fp.write(buf)
if cmpr:
buf = cmpr.flush()
compress_size = compress_size + len(buf)
self.fp.write(buf)
zinfo.compress_size = compress_size
else:
zinfo.compress_size = file_size
zinfo.CRC = CRC
zinfo.file_size = file_size
if not zip64 and self._allowZip64:
if file_size > ZIP64_LIMIT:
raise RuntimeError('File size has increased during compressing')
if compress_size > ZIP64_LIMIT:
raise RuntimeError('Compressed size larger than uncompressed size')
# Seek backwards and write file header (which will now include
# correct CRC and file sizes)
position = self.fp.tell() # Preserve current position in file
self.fp.flush()
self.filelist.append(zinfo)
self.NameToInfo[zinfo.filename] = zinfo
注意事项
>我是python的新手,所以我上面写的代码可能不是很优化.
>请在这里https://github.com/najela/EnhancedZipFile为github上的项目做贡献