Revert "ERR: include original error message for missing required dependencies (pandas-dev#26665)"

This reverts commit 047d32d.

Author: jorisvandenbossche

doc/source/whatsnew/v0.25.0.rst

@@ -82,7 +82,7 @@ Other Enhancements
 - :meth:`DataFrame.query` and :meth:`DataFrame.eval` now supports quoting column names with backticks to refer to names with spaces (:issue:`6508`)
 - :func:`merge_asof` now gives a more clear error message when merge keys are categoricals that are not equal (:issue:`26136`)
 - :meth:`pandas.core.window.Rolling` supports exponential (or Poisson) window type (:issue:`21303`)
-- Error message for missing required imports now includes the original ImportError's text (:issue:`23868`)
+-
 
 .. _whatsnew_0250.api_breaking:
 

pandas/__init__.py

@@ -10,13 +10,11 @@
     try:
         __import__(dependency)
     except ImportError as e:
-        missing_dependencies.append((dependency, e))
+        missing_dependencies.append(dependency)
 
 if missing_dependencies:
-    msg = "Unable to import required dependencies:"
-    for dependency, e in missing_dependencies:
-        msg += "\n{0}: {1}".format(dependency, str(e))
-    raise ImportError(msg)
+    raise ImportError(
+        "Missing required dependencies {0}".format(missing_dependencies))
 del hard_dependencies, dependency, missing_dependencies
 
 # numpy compat

pandas/tests/test_base.py

@@ -1,9 +1,7 @@
 from datetime import datetime, timedelta
-from importlib import reload
 from io import StringIO
 import re
 import sys
-from unittest.mock import patch
 
 import numpy as np
 import pytest
@@ -1343,28 +1341,3 @@ def test_to_numpy_dtype(as_series):
     expected = np.array(['2000-01-01T05', '2001-01-01T05'],
                         dtype='M8[ns]')
     tm.assert_numpy_array_equal(result, expected)
-
-
-@patch("builtins.__import__")
-def test_missing_required_dependency(mock_import):
-    def mock_import_fail(name, *args, **kwargs):
-        if name == "numpy":
-            raise ImportError("cannot import name numpy")
-        elif name == "pytz":
-            raise ImportError("cannot import name some_dependency")
-        elif name == "dateutil":
-            raise ImportError("cannot import name some_other_dependency")
-        else:
-            return __import__(name, *args, **kwargs)
-
-    mock_import.side_effect = mock_import_fail
-
-    expected_msg = (
-        "Unable to import required dependencies:"
-        "\nnumpy: cannot import name numpy"
-        "\npytz: cannot import name some_dependency"
-        "\ndateutil: cannot import name some_other_dependency"
-    )
-
-    with pytest.raises(ImportError, match=expected_msg):
-        reload(pd)