Add tests for error message

Author: rhshadrach

pandas/tests/tslibs/test_timezones.py

@@ -3,6 +3,9 @@
     timedelta,
     timezone,
 )
+import subprocess
+import sys
+import textwrap
 
 import dateutil.tz
 import pytest
@@ -16,6 +19,24 @@
 from pandas import Timestamp
 
 
+def test_no_timezone_data():
+    # https://github.com/pandas-dev/pandas/pull/63335
+    # Test error message when timezone data is not available.
+    msg = "'No time zone found with key Europe/Brussels'"
+    code = textwrap.dedent(
+        f"""\
+        import sys, zoneinfo, pandas as pd
+        sys.modules['tzdata'] = None
+        zoneinfo.reset_tzpath(['/path/to/nowhere'])
+        try:
+            pd.to_datetime('2012-01-01').tz_localize('Europe/Brussels')
+        except zoneinfo.ZoneInfoNotFoundError as err:
+            assert str(err) == "{msg}"
+        """
+    )
+    subprocess.check_call([sys.executable, "-c", code])
+
+
 def test_is_utc(utc_fixture):
     tz = timezones.maybe_get_tz(utc_fixture)
     assert timezones.is_utc(tz)