def mi_intersection(left: pd.MultiIndex,
right: pd.MultiIndex) -> pd.MultiIndex: # pragma: no cover
"""Intersection of MultiIndexes, preserving order.
Fix https://github.com/pandas-dev/pandas/issues/31325
"""
if left.equals(right):
return left
lvals = left._ndarray_values
rvals = right._ndarray_values
uniq_tuples = None # flag whether _inner_indexer was successful
if left.is_monotonic and right.is_monotonic:
try:
uniq_tuples = left._inner_indexer(lvals, rvals)[0]
except TypeError:
pass # noqa:WPS420
if uniq_tuples is None:
right_uniq = set(rvals)
seen: Set[Tuple] = set()
uniq_tuples = [
x for x in lvals if x in right_uniq
and not (x in seen or seen.add(x)) # type: ignore
]
names = left.names if left.names == right.names else None
if len(uniq_tuples) == 0:
return pd.MultiIndex(
levels=left.levels,
codes=[[]] * left.nlevels,
names=names,
verify_integrity=False,
)
return pd.MultiIndex.from_tuples(uniq_tuples, sortorder=0, names=names)
