Modify test to check for private modules (#25935)

Author: ryankarlos

pandas/tests/api/test_api.py

@@ -11,7 +11,7 @@ def check(self, namespace, expected, ignored=None):
         # ignored ones
         # compare vs the expected
 
-        result = sorted(f for f in dir(namespace) if not f.startswith('_'))
+        result = sorted(f for f in dir(namespace) if not f.startswith('__'))
         if ignored is not None:
             result = sorted(list(set(result) - set(ignored)))
 
@@ -93,6 +93,12 @@ class TestPDApi(Base):
     # these are already deprecated; awaiting removal
     deprecated_funcs = []
 
+    # private modules in pandas namespace
+    private_modules = ['_config', '_hashtable', '_lib', '_libs',
+                       '_np_version_under1p14', '_np_version_under1p15',
+                       '_np_version_under1p16', '_np_version_under1p17',
+                       '_tslib', '_typing', '_version']
+
     def test_api(self):
 
         self.check(pd,
@@ -103,7 +109,7 @@ def test_api(self):
                    self.funcs + self.funcs_option +
                    self.funcs_read + self.funcs_to +
                    self.deprecated_funcs_in_future +
-                   self.deprecated_funcs,
+                   self.deprecated_funcs + self.private_modules,
                    self.ignored)