python USES the module zlib to compress and extract strings and files

The zlib module in python is used to compress or extract data for saving and transmission. It is the basis for other compression tools. Let's take a look at how python USES the module zlib to compress and extract strings and files. Without further ado, let's look at the sample code.

Example 1: compressing and decompressing strings

import zlib
message = 'abcd1234'
compressed = zlib.compress(message)
decompressed = zlib.decompress(compressed)

print 'original:', repr(message)
print 'compressed:', repr(compressed)
print 'decompressed:', repr(decompressed)

The results of

original: 'abcd1234'
compressed: 'x\x9cKLJN1426\x01\x00\x0b\xf8\x02U'
decompressed: 'abcd1234'

Example 2: compressing and decompressing files

import zlib
def compress(infile, dst, level=9):
 infile = open(infile, 'rb')
 dst = open(dst, 'wb')
 compress = zlib.compressobj(level)
 data = infile.read(1024)
 while data:
  dst.write(compress.compress(data))
  data = infile.read(1024)
 dst.write(compress.flush())

def decompress(infile, dst):
 infile = open(infile, 'rb')
 dst = open(dst, 'wb')
 decompress = zlib.decompressobj()
 data = infile.read(1024)
 while data:
  dst.write(decompress.decompress(data))
  data = infile.read(1024)
 dst.write(decompress.flush())

if __name__ == "__main__":
 compress('in.txt', 'out.txt')
 decompress('out.txt', 'out_decompress.txt')

The results of

Generate the file

out_decompress.txt out.txt

Problem - handling object oversize exceptions

>>> import zlib
>>> a = '123'
>>> b = zlib.compress(a)
>>> b
'x\x9c342\x06\x00\x01-\x00\x97'
>>> a = 'a' * 1024 * 1024 * 1024 * 10
>>> b = zlib.compress(a)
Traceback (most recent call last):
 File "<stdin>", line 1, in <module>
OverflowError: size does not fit in an int

conclusion