(CkPython) Unzip Binary File to Stream

Demonstrates how to unzip a large binary file to a stream to allow the application to process the uncompressed bytes chunk by chunk.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

# This requires the Chilkat Zip API to have been previously unlocked.
# See Unlock Chilkat Zip for sample code.

zip = chilkat.CkZip()

# First open a .zip.
success = zip.OpenZip("qa_data/zips/big.zip")
if (success != True):
    print(zip.lastErrorText())
    sys.exit()

# Get the entry to be unzipped to a stream..
# entry is a CkZipEntry
entry = zip.GetEntryByIndex(0)
if (zip.get_LastMethodSuccess() != True):
    print(zip.lastErrorText())
    sys.exit()

dataStream = chilkat.CkStream()

# unzipTask is a CkTask
unzipTask = entry.UnzipToStreamAsync(dataStream)
if (entry.get_LastMethodSuccess() != True):
    print(entry.lastErrorText())

    sys.exit()

# Start the background unzip thread.
unzipTask.Run()

# We'll read the uncompressed data chunk-by-chunk and write to an output file.
fac = chilkat.CkFileAccess()
success = fac.OpenForWrite("qa_output/out.dat")
if (success != True):
    print(fac.lastErrorText())

    sys.exit()

# Read the stream.  (this is reading the unzipped file data)
bd = chilkat.CkBinData()
while dataStream.get_EndOfStream() != True :
    # Get the next chunk of decompressed bytes.
    dataStream.ReadBd(bd)
    # Do something with it..
    # In this simple example, we'll just write to the file.
    fac.FileWriteBd(bd,0,0)
    # Clear for the next read.
    bd.Clear()

fac.FileClose()

print("Success.")