🐛 update to make it pandas 2 compatible

src/njab/pandas/__init__.py

@@ -122,8 +122,8 @@ def combine_value_counts(X: pd.DataFrame, dropna=True) -> pd.DataFrame:
     """
     """
     """
-    _df = pd.DataFrame()
+    freq_targets = list()
     for col in X.columns:
-        _df = _df.join(X[col].value_counts(dropna=dropna), how='outer')
-    freq_targets = _df.sort_index()
+        freq_targets.append(X[col].value_counts(dropna=dropna))
+    freq_targets = pd.concat(freq_targets, axis=1, sort=True)
     return freq_targets

test/test_pandas.py

@@ -1,8 +1,16 @@
 import pandas as pd
+
 import njab
 
 
 def test_thousands_display():
     njab.pandas.set_pandas_options()
     s = pd.Series([1_000_000])
     assert str(s)[4:13] == '1,000,000'
+
+
+def test_combine_value_counts():
+    df = pd.DataFrame({'a': [1, 2, 2, 2, 3, 3, 3], 'b': [1, 1, 1, 2, 2, 3, 3]})
+    exp = {'a': {1: 1, 2: 3, 3: 3}, 'b': {1: 3, 2: 2, 3: 2}}
+    act = njab.pandas.combine_value_counts(df).to_dict()
+    assert act == exp