import re
s = "mengganti, maaf, ppuuutttiiiihhh, mmmmeeeeerrrraaaah, maaagggz"
print(re.sub(
r"([^\sag])\1+",
r"\1",
re.sub(r"([ag])\1+", r"\1\1", s))
)
aW1wb3J0IHJlCgpzID0gIm1lbmdnYW50aSwgbWFhZiwgcHB1dXV0dHRpaWlpaGhoLCBtbW1tZWVlZWVycnJyYWFhYWgsIG1hYWFnZ2d6IgoKcHJpbnQocmUuc3ViKAogICAgICAgIHIiKFteXHNhZ10pXDErIiwKICAgICAgICByIlwxIiwKICAgICAgICByZS5zdWIociIoW2FnXSlcMSsiLCByIlwxXDEiLCBzKSkKKQ==