def test_ensure_unique_column():
df = pd.DataFrame({"a": [0, 1, 0], "b": [1.0, 0.0, 1.0]})
out = ensure_unique_column("a", df)
assert out == "_a_"
out = ensure_unique_column("c", df)
assert out == "c"
out = ensure_unique_column("a", df, "=")
assert out == "=a="
df["_a_"] = -1
out = ensure_unique_column("a", df)
assert out == "__a__"
def _minimize_multiindex(df: DataFrame) -> DataFrame:
index_cols = list(df.index.names)
orig_names = index_cols[:]
for i, col in enumerate(index_cols):
col = ensure_unique_column(col, df)
index_cols[i] = col
df.index.names = index_cols
df = df.reset_index()
df = df.set_index(index_cols)
df.index.names = orig_names
return df