As a collary to the previous exercise, write a decompression program for the produced strings.

Hint: Just do the opposite of what you did in the previous exercise: rebuild the half-byte-list. That list is then easily converted back to the original string.

Assignment

Write a function decompress that takes a byte string (bytes) that was produced by the compression program from the previous exercise. The function must return the text (str) that was compressed into that byte string.

Watch out for the zero half-byte that may have been added at the end of the byte string to complete its last byte. Such a half-byte is padding, not the start of an unencoded character.

Example

>>> decompress(b'\x04\x81\xbb@,\xf0wI\xba\x02\x10')
'Hello, world!'
>>> decompress(b'\x124Vx\x9a\xbc\xde\xf0')
'etaoinshrdlcum '
>>> decompress(b'\x05\x10W\x04PR\x05@Y')
'QWERTY'
>>> decompress(b'')
''