rsplit and join could be used to simulate the effects of an rreplace

>>> 'XXX'.join('mississippi'.rsplit('iss', 1))
'missXXXippi'

You could put the translations into a dict, and also combine the search-patterns into a single regular expression, which gives priority to the longer patterns. Then use the callback argument that re.sub accepts to make the replacement using the dict.

import re

trans = {
    "00": "a",
    "11": "b",
    "01": "c",
    "10": "d",
    "0000": "e",
    "1111": "f",
    "0101": "g",
    "1010": "h"
}

regex = "|".join(sorted(trans.keys(), key=len, reverse=True))

# demo
s =  "0000000110110110100111111111"
result = re.sub(regex, lambda x: trans[x.group(0)], s)
print(result)  # eacdbchcff

There's no such function built in, or, for that matter, available in any extension library I know of.

It's pretty easy to do yourself, though. Say the int is n and you want to shift it left by s bits.

First flip all the bits of n (change all 0 bits to 1, and all 1 bits to 0). Then shift left by s. That adds s 0 bits on the right. Then flip the bits again. The new trailing 0 bits are changed to 1 bits, and the original bits of n are restored.

>>> n = 5
>>> bin(n)
'0b101'
>>> ~(~n << 6)
383
>>> bin(_)
'0b101111111'