将python中的zip文件保存到磁盘

Question

我在数据库中有一个bytea object，它是一个 zip 文件，我可以检索它并将其作为 zip 文件读取，但我也想将它保存到磁盘。

我不知道如何将zf_model写入磁盘。 我也尝试过zf.write(io.BytesIO(model.model_file)) ，即不首先转换为 zip，但这也不起作用。

这是我试过的：

from zipfile import ZipFile
from io import BytesIO
        
#Retrieve the zip file from database (zip file is in a field called model_file for object: Model)
model = Model().query.filter_by(param = "test").first()
#convert the retrieved object to a zip file
zf_model = ZipFile(BytesIO(model.model_file), "w")
    
tempfile = "/tmp/test.zip"

with zipfile.ZipFile(tempfile, "w", compression=zipfile.ZIP_DEFLATED) as zf:
    zf.write(zf_model)

给出错误：

TypeError: a bytes-like object is required, not 'ZipFile'

尝试直接写入bytea object

with open(tempfile, 'w+') as f:
    f.write(model.model_file)      

给出错误：

TypeError: write() argument must be str, not bytes

Answer 1

如果您从数据库中检索已经压缩的文件，您可以根本不使用 ZipFile 将其写入磁盘。

#Retrieve the zip file from database (zip file is in a field called model_file for object: Model)
model = Model().query.filter_by(param = "test").first()

tempfile = "/tmp/test.zip"

with open(tempfile, 'wb') as f:
    f.write(model.model_file)

无论如何，如果您的 model 存储纯字节数据（不是压缩数据），您可以执行以下操作

from zipfile import ZipFile

#Retrieve the zip file from database 
model = Model().query.filter_by(param = "test").first()

tempfile = "/tmp/test.zip"

with ZipFile(tempfile, 'w') as f:
    f.writestr('name_of_file_in_zip_archive.txt', model.model_file)