Add test case for DataFrame.from_dict

Author: mrkn

pandas/tests/frame/common.py

@@ -1,5 +1,9 @@
 from __future__ import annotations
 
+from collections.abc import (
+    Mapping,
+    Sequence,
+)
 from typing import TYPE_CHECKING
 
 from pandas import (
@@ -11,6 +15,35 @@
     from pandas._typing import AxisInt
 
 
+class DictWrapper(Mapping):
+    _dict: dict
+
+    def __init__(self, d: dict) -> None:
+        self._dict = d
+
+    def __getitem__(self, key):
+        return self._dict[key]
+
+    def __iter__(self):
+        return self._dict.__iter__()
+
+    def __len__(self):
+        return self._dict.__len__()
+
+
+class ListWrapper(Sequence):
+    _list: list
+
+    def __init__(self, lst: list) -> None:
+        self._list = lst
+
+    def __getitem__(self, i):
+        return self._list[i]
+
+    def __len__(self):
+        return self._list.__len__()
+
+
 def _check_mixed_float(df, dtype=None):
     # float16 are most likely to be upcasted to float32
     dtypes = {"A": "float32", "B": "float32", "C": "float16", "D": "float64"}

pandas/tests/frame/constructors/test_from_dict.py

@@ -11,8 +11,10 @@
     MultiIndex,
     RangeIndex,
     Series,
+    date_range,
 )
 import pandas._testing as tm
+from pandas.tests.frame.common import DictWrapper
 
 
 class TestFromDict:
@@ -135,6 +137,15 @@ def test_constructor_from_ordered_dict(self):
         result = DataFrame.from_dict(a, orient="index")
         tm.assert_frame_equal(result, expected)
 
+    def test_constructor_from_mappinng(self):
+        idx = Index(date_range("20130101", periods=3, tz="US/Eastern"), name="foo")
+        dr = date_range("20130110", periods=3)
+
+        # construction
+        expected = DataFrame(DictWrapper({"A": idx, "B": dr}))
+        result = DataFrame.from_dict(DictWrapper({"A": idx, "B": dr}))
+        tm.assert_frame_equal(result, expected)
+
     def test_from_dict_columns_parameter(self):
         # GH#18529
         # Test new columns parameter for from_dict that was added to make

pandas/tests/frame/test_constructors.py

@@ -5,11 +5,7 @@
     defaultdict,
     namedtuple,
 )
-from collections.abc import (
-    Iterator,
-    Mapping,
-    Sequence,
-)
+from collections.abc import Iterator
 from dataclasses import make_dataclass
 from datetime import (
     date,
@@ -65,6 +61,10 @@
     SparseArray,
     TimedeltaArray,
 )
+from pandas.tests.frame.common import (
+    DictWrapper,
+    ListWrapper,
+)
 
 MIXED_FLOAT_DTYPES = ["float16", "float32", "float64"]
 MIXED_INT_DTYPES = [
@@ -79,35 +79,6 @@
 ]
 
 
-class DictWrapper(Mapping):
-    _dict: dict
-
-    def __init__(self, d: dict) -> None:
-        self._dict = d
-
-    def __getitem__(self, key):
-        return self._dict[key]
-
-    def __iter__(self):
-        return self._dict.__iter__()
-
-    def __len__(self):
-        return self._dict.__len__()
-
-
-class ListWrapper(Sequence):
-    _list: list
-
-    def __init__(self, lst: list) -> None:
-        self._list = lst
-
-    def __getitem__(self, i):
-        return self._list[i]
-
-    def __len__(self):
-        return self._list.__len__()
-
-
 class TestDataFrameConstructors:
     def test_constructor_from_ndarray_with_str_dtype(self):
         # If we don't ravel/reshape around ensure_str_array, we end up
@@ -2934,7 +2905,7 @@ def test_from_dict(self):
         tm.assert_series_equal(df["A"], Series(idx, name="A"))
         tm.assert_series_equal(df["B"], Series(dr, name="B"))
 
-    def test_from_dict_with_mapping(self):
+    def test_from_mapping(self):
         idx = Index(date_range("20130101", periods=3, tz="US/Eastern"), name="foo")
         dr = date_range("20130110", periods=3)