unable unzip password protected .gz file in GCS bucket using Python

Question

Trying to unzip password protected file in GCS but getting error in below code. Below code work fine with normal .gz files but fails to unzip password protected files.

storage_client = storage.Client()
source_bucket = 'bucket'
source_bucket1 = storage_client.bucket(source_bucket)
blob = source_bucket1.blob("path/filename.gz")
zipbytes = io.BytesIO(blob.download_as_string())
        print(zipbytes)
        if is_zipfile(zipbytes):
            with ZipFile(zipbytes, 'r') as myzip:
                for contentfilename in myzip.namelist():
                    contentfile = myzip.read(contentfilename)
                    contentfilename = contentfilename[:-3]
                    blob1 = bucket.blob(contentfilename)
                    blob1.upload_from_string(contentfile)
                    print(f'File decompressed from {zipfilename_with_path} to {contentfilename}')
        blob.delete()

GZip (`.gz`) files are not Zip files and they don't support encryption. — Klaus D., Feb 16 '22 at 17:04
have tried ```with ZipFile(blob, 'r') as zf: zf.printdir() print('Extracting all the files now...') zf.extractall(pwd=b'*********') ``` as well but getting error as "Blob' object has no attribute 'seek'" — abhi, Feb 16 '22 at 17:13

score 0 · Answer 1 · answered Feb 16 '22 at 17:10

You can use Python, e.g. from a Cloud Function:

from google.cloud import storage
    from zipfile import ZipFile
    from zipfile import is_zipfile
    import io

    def zipextract(bucketname, zipfilename_with_path):

        storage_client = storage.Client()
        bucket = storage_client.get_bucket(bucketname)

        destination_blob_pathname = zipfilename_with_path
        
        blob = bucket.blob(destination_blob_pathname)
        zipbytes = io.BytesIO(blob.download_as_string())

        if is_zipfile(zipbytes):
            with ZipFile(zipbytes, 'r') as myzip:
                for contentfilename in myzip.namelist():
                    contentfile = myzip.read(contentfilename)
                    blob = bucket.blob(zipfilename_with_path + "/" + contentfilename)
                    blob.upload_from_string(contentfile)

    zipextract("mybucket", "path/file.zip") # if the file is gs://mybucket/path/file.zip

Thanks for your reply but this logic is working on .gz files and not on password protected .gz files. — abhi, Feb 16 '22 at 17:15

score 0 · Accepted Answer · answered Feb 28 '22 at 14:42

Am able to read .csv.gz password protected file using below logic. All of this is done in memory. It has performance issue if the file is huge but works fine.

        storage_client = storage.Client()
        source_bucket = '<bucket-name>'
        source_bucket1 = storage_client.bucket(source_bucket)
        bukcet_folder = '/unzip'
        blob = source_bucket1.blob(path)
        zipbytes = io.BytesIO(blob.download_as_string())
        with ZipFile(zipbytes, 'r') as myzip:
            print("Inside the zipfiles loop")
            with myzip.open('filename.csv',pwd=b'password') as myfile:
                print("Inside zip 2 loop")
                contentfile = myfile.read()
                contentfilename = bucket_folder + destination_file_path
                blob1 = source_bucket1.blob(contentfilename)
                blob1.upload_from_string(contentfile)
              ```

unable unzip password protected .gz file in GCS bucket using Python

2 Answers2