Chilkat2-Python

Unzip One File to a Stream

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Demonstrates how to unzip a particular file contained within a .zip archive to a Chilkat stream. Chilkat2-Python

import sys
import chilkat2

success = False

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

zip = chilkat2.Zip()

# First open a .zip.
success = zip.OpenZip("qa_data/hamlet.zip")
if (success == False):
    print(zip.LastErrorText)
    sys.exit()

# Find the entry to be unzipped to a stream..
entry = chilkat2.ZipEntry()
success = zip.EntryMatching("*hamlet.xml",entry)
if (success == False):
    print(zip.LastErrorText)
    sys.exit()

# There are three ways we can unzip (inflate) to a stream.
# 
# 1) Set a sink file on the stream object and call UnzipToStream synchronously.
#    This unzips to the stream's sink (which is to simply unzip to a file in the filesystem).
# 
# 2) Create a stream object and call UnzipToStreamAsync.  This starts the unzip in a background
#    thread (after Task.Run is called).  Your application can then read the unzipped (inflated) file
#    directly from the stream.
# 
# 3) (not shown in this example) Unzip to a stream object that is the source of something else.
#    

# ----------------------------------------------------------------
# Case 1: Unzip to a file by setting the sink of streamA to a file.
streamA = chilkat2.Stream()
streamA.SinkFile = "qa_output/hamletA.xml"

success = entry.UnzipToStream(streamA)
if (success != True):
    print(entry.LastErrorText)
    sys.exit()

# Close the stream to close the output file.
success = streamA.WriteClose()

# ----------------------------------------------------------------
# Case 2a: Uzip to a stream asynchronously. 
streamB = chilkat2.Stream()

# unzipTask is a CkTask
unzipTask = entry.UnzipToStreamAsync(streamB)
if (entry.LastMethodSuccess != True):
    print(entry.LastErrorText)
    sys.exit()

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

# Read the stream.  (this is reading the unzipped file data)
sb = chilkat2.StringBuilder()
while streamB.EndOfStream != True :
    # Each call to ReadSb appends to the contents of sb.
    streamB.ReadSb(sb)

sb.WriteFile("qa_output/hamletB.xml","utf-8",False)

print("Success.")

# ----------------------------------------------------------------
# Case 2b: Uzip to a stream asynchronously and emit output while reading. 
streamC = chilkat2.Stream()

# unzipTask is a CkTask
unzipTask = entry.UnzipToStreamAsync(streamC)
if (entry.LastMethodSuccess != True):
    print(entry.LastErrorText)
    sys.exit()

unzipTask.Run()

while streamC.EndOfStream != True :
    s = streamC.ReadString()
    print(s)

print("Success.")