[BUG] Extend fill_empty's column_names type range

CHANGELOG.md

@@ -10,6 +10,7 @@
 -   [ENH] Add `xlsx_table`, for reading tables from an Excel sheet. @samukweku
 -   [ENH] minor improvements for conditional_join; equality only joins are no longer supported; there has to be at least one non-equi join present. @samukweku
 -   [BUG] `sort_column_value_order` no longer mutates original dataframe.
+-   [BUG] Extend `fill_empty`'s `column_names` type range. Issue #998. @Zeroto521
 
 ## [v0.22.0] - 2021-11-21
 

janitor/functions/fill.py

@@ -1,3 +1,4 @@
+from collections.abc import Iterable as abcIterable
 from enum import Enum
 from operator import methodcaller
 from typing import Hashable, Iterable, Union
@@ -145,7 +146,7 @@ def fill_empty(
     return _fill_empty(df, column_names, value=value)
 
 
-@dispatch(pd.DataFrame, (list, tuple))
+@dispatch(pd.DataFrame, abcIterable)
 def _fill_empty(df, column_names, value=None):
     """Fill empty function for the case that column_names is list or tuple."""
     fill_mapping = {c: value for c in column_names}

tests/functions/test_fill_empty.py

@@ -1,4 +1,5 @@
 import pytest
+import pandas as pd
 
 
 @pytest.mark.functions
@@ -11,3 +12,22 @@ def test_fill_empty(null_df):
 def test_fill_empty_column_string(null_df):
     df = null_df.fill_empty(column_names="2", value=3)
     assert set(df.loc[:, "2"]) == set([3])
+
+
+@pytest.mark.functions
+@pytest.mark.parametrize(
+    "column_names",
+    [
+        (0, 1, "2", "3"),  # tuple
+        [0, 1, "2", "3"],  # list
+        {0, 1, "2", "3"},  # set
+        ({0: 0, 1: 1, "2": "2", "3": "3"}).keys(),  # dict key
+        ({0: 0, 1: 1, "2": "2", "3": "3"}).values(),  # dict value
+        pd.Index([0, 1, "2", "3"]),  # Index
+    ],
+)
+def test_column_names_iterable_type(null_df, column_names):
+    result = null_df.fill_empty(column_names=column_names, value=3)
+    excepted = null_df.fillna(3)
+
+    assert result.equals(excepted)