1999-03-12 15:07:59 -04:00
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#!/usr/bin/env python
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1997-05-28 13:13:21 -03:00
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import zlib, sys
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if len(sys.argv)>1: filename=sys.argv[1]
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else: filename='zlibdemo.py'
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print 'Reading', filename
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f=open(filename, 'r') # Get the data to compress
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s=f.read()
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f.close()
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# First, we'll compress the string in one step
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comptext=zlib.compress(s, 1)
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decomp=zlib.decompress(comptext)
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print '1-step compression: (level 1)'
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print ' Original:', len(s), 'Compressed:', len(comptext),
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print 'Uncompressed:', len(decomp)
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# Now, let's compress the string in stages; set chunk to work in smaller steps
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chunk=256
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compressor=zlib.compressobj(9)
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decompressor=zlib.decompressobj()
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comptext=decomp=''
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for i in range(0, len(s), chunk):
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comptext=comptext+compressor.compress(s[i:i+chunk])
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comptext=comptext+compressor.flush() # Don't forget to call flush()!!
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for i in range(0, len(comptext), chunk):
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decomp=decomp+decompressor.decompress(comptext[i:i+chunk])
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decomp=decomp+decompressor.flush()
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print 'Progressive compression (level 9):'
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print ' Original:', len(s), 'Compressed:', len(comptext),
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print 'Uncompressed:', len(decomp)
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