Append In-Memory Data to Existing Zip w/out Rewriting Entire Zip

Demonstrates how to use the QuickAppend method to append in-memory data (string or byte array) to an existing .zip archive. This method works by editing the existing .zip -- it does not rewrite or recompress the contents of the existing .zip. It is the fastest way to append additional files or data to a pre-existing large .zip archive. Note: The QuickAppend method is new and available in the pre-release downloads, or in official releases dated after 6-October-2007.

Download Chilkat Python Library

import sys
import chilkat

zip = chilkat.CkZip()

#  Any string unlocks the component for the 1st 30-days.
success = zip.UnlockComponent("Anything for 30-day trial")
if (success != True):
    print zip.lastErrorText()
    sys.exit()

#  The NewZip method only initializes the Zip object -- it does
#  not create or write a .zip file.
success = zip.NewZip("notUsed.zip")
if (success != True):
    print zip.lastErrorText()
    sys.exit()

inZipFilename = "something.txt"
strData = "abcdefghijklmnopqrstuvwxyz1234567890"
strCharset = "iso-8859-1"
#  Append a string as a file to the existing zip object.
#  Please read the notes about strCharset below.
zip.AppendString2(inZipFilename,strData,strCharset)

#  Note: The AppendString method is identical to AppendString2,
#  except the strCharset argument is omitted and it is assumed
#  you desire the ANSI charset.

#  Note: You may append a byte array (or Variant containing
#  a byte array for ActiveX users) by calling AppendData.

#  Appends the contents of this zip object to the preExisting.zip
#  zip archive.  preExisting.zip is opened, and the files
#  referenced by this zip object are streamed in, compressed,
#  and appended to the end of the archive.
success = zip.QuickAppend("preExisting.zip")
if (success != True):
    print zip.lastErrorText()
    sys.exit()

print "Success!"

#  Note about strCharset:
#  string variables in many programming language are Unicode.
#  It is likely that you don't want to create .zip that contains
#  a text file that will unzip to Unicode characters (2 bytes/char).
#  The strCharset argument allows you to specify the exact
#  charset to use.  When the string is added to the .zip, it
#  is first converted to this charset.  English strings
#  may use "us-ascii".  Western-European languages typically
#  use "iso-8859-1" or "windows-1252".  Japanese might choose
#  between "shift_jis", "iso-2022-jp", "euc-jp", etc.
#  Chilkat supports all major character encodings.
#  You may always use "ansi" or "utf-8".

#  Note: Additional files, directory trees, or in-memory data
#  can be appended by calling AppendOneFileOrDir, AppendFiles,
#  AppendString, AppendData, etc. multiple times.
#  Whatever files and/or in-memory data that are referenced by
#  this zip object will be appended to preExisting.zip when
#  QuickAppend is called.