stream-zip CircleCI Test Coverage

Python function to construct a ZIP archive on the fly – without having to store the entire ZIP in memory or disk. This is useful in memory-constrained environments, or when you would like to start returning compressed data before you’ve even retrieved all the uncompressed data. Generating ZIPs on-demand in a web server is a typical use case for stream-zip.

Offers similar functionality to zipfly, but with a different API, and does not use Python’s zipfile module under the hood.

To unZIP files on the fly try stream-unzip.


pip install stream-zip


from datetime import datetime
from stream_zip import stream_zip

def unzipped_files():
    modified_at =
    perms = 0o600

    def file_1_data():
        yield b'Some bytes'

    def file_2_data():
        yield b'Some bytes'

    yield 'my-file-1.txt', modified_at, perms, file_1_data()
    yield 'my-file-2.txt', modified_at, perms, file_2_data()

for zipped_chunk in stream_zip(unzipped_files()):


It’s not possible to completely stream-write ZIP files. Small bits of metadata for each member file, such as its name, must be placed at the end of the ZIP. In order to do this, stream-unzip buffers this metadata in memory until it can be output.


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