Checking in zlib demo.

Demo/zlib/zlibdemo.py

@@ -0,0 +1,36 @@
+#!/usr/local/bin/python
+
+import zlib, sys
+if len(sys.argv)>1: filename=sys.argv[1]
+else: filename='zlibdemo.py'
+print 'Reading', filename
+f=open(filename, 'r')		# Get the data to compress
+s=f.read()
+f.close()
+
+# First, we'll compress the string in one step
+comptext=zlib.compress(s, 1)
+decomp=zlib.decompress(comptext)
+
+print '1-step compression: (level 1)'
+print '    Original:', len(s), 'Compressed:', len(comptext),
+print 'Uncompressed:', len(decomp)
+
+# Now, let's compress the string in stages; set chunk to work in smaller steps
+
+chunk=256
+compressor=zlib.compressobj(9)
+decompressor=zlib.decompressobj()
+comptext=decomp=''
+for i in range(0, len(s), chunk):
+    comptext=comptext+compressor.compress(s[i:i+chunk])
+comptext=comptext+compressor.flush()	# Don't forget to call flush()!!
+
+for i in range(0, len(comptext), chunk):
+    decomp=decomp+decompressor.decompress(comptext[i:i+chunk])
+decomp=decomp+decompressor.flush()
+
+print 'Progressive compression (level 9):'
+print '    Original:', len(s), 'Compressed:', len(comptext),
+print 'Uncompressed:', len(decomp)
+