all Python 3bz2function

bz2.compress()

in-memory compression

Compresses bytes with bzip2 in a single call and returns the compressed bytes. For data that fits in memory as a whole.

Syntax

data = bz2.compress(data, compresslevel=9)

It accepts bytes-like objects only: encode a string first, or you get TypeError. On small data the result can be longer than the input — the format has a header. bzip2 squeezes text tighter than zlib but is noticeably slower; the output depends on the library version, so tests should check a round trip rather than compare compressed bytes.

Examples

import bz2
text = 'повтор ' * 1000
packed = bz2.compress(text.encode('utf-8'))
print(len(packed) < len(text))  # → True
print(bz2.decompress(packed).decode('utf-8') == text)  # → True
try:
    bz2.compress('строка')
except TypeError:
    print('нужны bytes')  # → нужны bytes

See also

Common errors

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