Modernize sqlite3 tests

Update current tests that use old pattern with assertRaises
to make them more maintainable.

6 files changed, 62 insertions, 257 deletions

diff --git a/Lib/sqlite3/test/dbapi.py b/Lib/sqlite3/test/dbapi.py
index 78c27d7..6057805 100644
--- a/Lib/sqlite3/test/dbapi.py
+++ b/Lib/sqlite3/test/dbapi.py
@@ -122,11 +122,8 @@ class ConnectionTests(unittest.TestCase):
 
     def CheckFailedOpen(self):
         YOU_CANNOT_OPEN_THIS = "/foo/bar/bla/23534/mydb.db"
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             con = sqlite.connect(YOU_CANNOT_OPEN_THIS)
-        except sqlite.OperationalError:
-            return
-        self.fail("should have raised an OperationalError")
 
     def CheckClose(self):
         self.cx.close()
@@ -202,22 +199,12 @@ class CursorTests(unittest.TestCase):
         self.cu.execute("delete from test")
 
     def CheckExecuteIllegalSql(self):
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             self.cu.execute("select asdf")
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError:
-            return
-        except:
-            self.fail("raised wrong exception")
 
     def CheckExecuteTooMuchSql(self):
-        try:
+        with self.assertRaises(sqlite.Warning):
             self.cu.execute("select 5+4; select 4+5")
-            self.fail("should have raised a Warning")
-        except sqlite.Warning:
-            return
-        except:
-            self.fail("raised wrong exception")
 
     def CheckExecuteTooMuchSql2(self):
         self.cu.execute("select 5+4; -- foo bar")
@@ -232,13 +219,8 @@ class CursorTests(unittest.TestCase):
             """)
 
     def CheckExecuteWrongSqlArg(self):
-        try:
+        with self.assertRaises(ValueError):
             self.cu.execute(42)
-            self.fail("should have raised a ValueError")
-        except ValueError:
-            return
-        except:
-            self.fail("raised wrong exception.")
 
     def CheckExecuteArgInt(self):
         self.cu.execute("insert into test(id) values (?)", (42,))
@@ -263,27 +245,18 @@ class CursorTests(unittest.TestCase):
 
     def CheckExecuteWrongNoOfArgs1(self):
         # too many parameters
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.execute("insert into test(id) values (?)", (17, "Egon"))
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
 
     def CheckExecuteWrongNoOfArgs2(self):
         # too little parameters
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.execute("insert into test(id) values (?)")
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
 
     def CheckExecuteWrongNoOfArgs3(self):
         # no parameters, parameters are needed
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.execute("insert into test(id) values (?)")
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
 
     def CheckExecuteParamList(self):
         self.cu.execute("insert into test(name) values ('foo')")
@@ -322,27 +295,18 @@ class CursorTests(unittest.TestCase):
 
     def CheckExecuteDictMappingTooLittleArgs(self):
         self.cu.execute("insert into test(name) values ('foo')")
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.execute("select name from test where name=:name and id=:id", {"name": "foo"})
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
 
     def CheckExecuteDictMappingNoArgs(self):
         self.cu.execute("insert into test(name) values ('foo')")
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.execute("select name from test where name=:name")
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
 
     def CheckExecuteDictMappingUnnamed(self):
         self.cu.execute("insert into test(name) values ('foo')")
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.execute("select name from test where name=?", {"name": "foo"})
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
 
     def CheckClose(self):
         self.cu.close()
@@ -403,32 +367,16 @@ class CursorTests(unittest.TestCase):
         self.cu.executemany("insert into test(income) values (?)", mygen())
 
     def CheckExecuteManyWrongSqlArg(self):
-        try:
+        with self.assertRaises(ValueError):
             self.cu.executemany(42, [(3,)])
-            self.fail("should have raised a ValueError")
-        except ValueError:
-            return
-        except:
-            self.fail("raised wrong exception.")
 
     def CheckExecuteManySelect(self):
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             self.cu.executemany("select ?", [(3,)])
-            self.fail("should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            return
-        except:
-            self.fail("raised wrong exception.")
 
     def CheckExecuteManyNotIterable(self):
-        try:
+        with self.assertRaises(TypeError):
             self.cu.executemany("insert into test(income) values (?)", 42)
-            self.fail("should have raised a TypeError")
-        except TypeError:
-            return
-        except Exception as e:
-            print("raised", e.__class__)
-            self.fail("raised wrong exception.")
 
     def CheckFetchIter(self):
         # Optional DB-API extension.
@@ -505,22 +453,15 @@ class CursorTests(unittest.TestCase):
         self.assertEqual(self.cu.connection, self.cx)
 
     def CheckWrongCursorCallable(self):
-        try:
+        with self.assertRaises(TypeError):
             def f(): pass
             cur = self.cx.cursor(f)
-            self.fail("should have raised a TypeError")
-        except TypeError:
-            return
-        self.fail("should have raised a ValueError")
 
     def CheckCursorWrongClass(self):
         class Foo: pass
         foo = Foo()
-        try:
+        with self.assertRaises(TypeError):
             cur = sqlite.Cursor(foo)
-            self.fail("should have raised a ValueError")
-        except TypeError:
-            pass
 
 @unittest.skipUnless(threading, 'This test requires threading.')
 class ThreadTests(unittest.TestCase):
@@ -719,22 +660,14 @@ class ExtensionTests(unittest.TestCase):
     def CheckScriptSyntaxError(self):
         con = sqlite.connect(":memory:")
         cur = con.cursor()
-        raised = False
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             cur.executescript("create table test(x); asdf; create table test2(x)")
-        except sqlite.OperationalError:
-            raised = True
-        self.assertEqual(raised, True, "should have raised an exception")
 
     def CheckScriptErrorNormal(self):
         con = sqlite.connect(":memory:")
         cur = con.cursor()
-        raised = False
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             cur.executescript("create table test(sadfsadfdsa); select foo from hurz;")
-        except sqlite.OperationalError:
-            raised = True
-        self.assertEqual(raised, True, "should have raised an exception")
 
     def CheckCursorExecutescriptAsBytes(self):
         con = sqlite.connect(":memory:")
@@ -772,59 +705,34 @@ class ClosedConTests(unittest.TestCase):
     def CheckClosedConCursor(self):
         con = sqlite.connect(":memory:")
         con.close()
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             cur = con.cursor()
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedConCommit(self):
         con = sqlite.connect(":memory:")
         con.close()
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.commit()
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedConRollback(self):
         con = sqlite.connect(":memory:")
         con.close()
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.rollback()
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedCurExecute(self):
         con = sqlite.connect(":memory:")
         cur = con.cursor()
         con.close()
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             cur.execute("select 4")
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedCreateFunction(self):
         con = sqlite.connect(":memory:")
         con.close()
         def f(x): return 17
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.create_function("foo", 1, f)
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedCreateAggregate(self):
         con = sqlite.connect(":memory:")
@@ -836,49 +744,29 @@ class ClosedConTests(unittest.TestCase):
                 pass
             def finalize(self):
                 return 17
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.create_aggregate("foo", 1, Agg)
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedSetAuthorizer(self):
         con = sqlite.connect(":memory:")
         con.close()
         def authorizer(*args):
             return sqlite.DENY
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.set_authorizer(authorizer)
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedSetProgressCallback(self):
         con = sqlite.connect(":memory:")
         con.close()
         def progress(): pass
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.set_progress_handler(progress, 100)
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
     def CheckClosedCall(self):
         con = sqlite.connect(":memory:")
         con.close()
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con()
-            self.fail("Should have raised a ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("Should have raised a ProgrammingError")
 
 class ClosedCurTests(unittest.TestCase):
     def setUp(self):
@@ -900,15 +788,9 @@ class ClosedCurTests(unittest.TestCase):
             else:
                 params = []
 
-            try:
+            with self.assertRaises(sqlite.ProgrammingError):
                 method = getattr(cur, method_name)
-
                 method(*params)
-                self.fail("Should have raised a ProgrammingError: method " + method_name)
-            except sqlite.ProgrammingError:
-                pass
-            except:
-                self.fail("Should have raised a ProgrammingError: " + method_name)
 
 def suite():
     module_suite = unittest.makeSuite(ModuleTests, "Check")
diff --git a/Lib/sqlite3/test/hooks.py b/Lib/sqlite3/test/hooks.py
index ede0bec..67653ae 100644
--- a/Lib/sqlite3/test/hooks.py
+++ b/Lib/sqlite3/test/hooks.py
@@ -33,19 +33,14 @@ class CollationTests(unittest.TestCase):
 
     def CheckCreateCollationNotCallable(self):
         con = sqlite.connect(":memory:")
-        try:
+        with self.assertRaises(TypeError) as cm:
             con.create_collation("X", 42)
-            self.fail("should have raised a TypeError")
-        except TypeError as e:
-            self.assertEqual(e.args[0], "parameter must be callable")
+        self.assertEqual(str(cm.exception), 'parameter must be callable')
 
     def CheckCreateCollationNotAscii(self):
         con = sqlite.connect(":memory:")
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             con.create_collation("collä", lambda x, y: (x > y) - (x < y))
-            self.fail("should have raised a ProgrammingError")
-        except sqlite.ProgrammingError as e:
-            pass
 
     @unittest.skipIf(sqlite.sqlite_version_info < (3, 2, 1),
                      'old SQLite versions crash on this test')
@@ -70,11 +65,9 @@ class CollationTests(unittest.TestCase):
             self.fail("the expected order was not returned")
 
         con.create_collation("mycoll", None)
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             result = con.execute(sql).fetchall()
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError as e:
-            self.assertEqual(e.args[0].lower(), "no such collation sequence: mycoll")
+        self.assertEqual(str(cm.exception), 'no such collation sequence: mycoll')
 
     def CheckCollationReturnsLargeInteger(self):
         def mycoll(x, y):
@@ -106,8 +99,8 @@ class CollationTests(unittest.TestCase):
         result = con.execute("""
             select x from (select 'a' as x union select 'b' as x) order by x collate mycoll
             """).fetchall()
-        if result[0][0] != 'b' or result[1][0] != 'a':
-            self.fail("wrong collation function is used")
+        self.assertEqual(result[0][0], 'b')
+        self.assertEqual(result[1][0], 'a')
 
     def CheckDeregisterCollation(self):
         """
@@ -117,12 +110,9 @@ class CollationTests(unittest.TestCase):
         con = sqlite.connect(":memory:")
         con.create_collation("mycoll", lambda x, y: (x > y) - (x < y))
         con.create_collation("mycoll", None)
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             con.execute("select 'a' as x union select 'b' as x order by x collate mycoll")
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError as e:
-            if not e.args[0].startswith("no such collation sequence"):
-                self.fail("wrong OperationalError raised")
+        self.assertEqual(str(cm.exception), 'no such collation sequence: mycoll')
 
 class ProgressTests(unittest.TestCase):
     def CheckProgressHandlerUsed(self):
diff --git a/Lib/sqlite3/test/regression.py b/Lib/sqlite3/test/regression.py
index 11adb30..85ace84 100644
--- a/Lib/sqlite3/test/regression.py
+++ b/Lib/sqlite3/test/regression.py
@@ -170,14 +170,8 @@ class RegressionTests(unittest.TestCase):
 
         con = sqlite.connect(":memory:")
         cur = Cursor(con)
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             cur.execute("select 4+5").fetchall()
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("should have raised ProgrammingError")
-
 
     def CheckStrSubclass(self):
         """
@@ -196,13 +190,8 @@ class RegressionTests(unittest.TestCase):
                 pass
 
         con = Connection(":memory:")
-        try:
+        with self.assertRaises(sqlite.ProgrammingError):
             cur = con.cursor()
-            self.fail("should have raised ProgrammingError")
-        except sqlite.ProgrammingError:
-            pass
-        except:
-            self.fail("should have raised ProgrammingError")
 
     def CheckCursorRegistration(self):
         """
@@ -223,13 +212,8 @@ class RegressionTests(unittest.TestCase):
         cur.executemany("insert into foo(x) values (?)", [(3,), (4,), (5,)])
         cur.execute("select x from foo")
         con.rollback()
-        try:
+        with self.assertRaises(sqlite.InterfaceError):
             cur.fetchall()
-            self.fail("should have raised InterfaceError")
-        except sqlite.InterfaceError:
-            pass
-        except:
-            self.fail("should have raised InterfaceError")
 
     def CheckAutoCommit(self):
         """
diff --git a/Lib/sqlite3/test/transactions.py b/Lib/sqlite3/test/transactions.py
index feb4fa1..eae26c4 100644
--- a/Lib/sqlite3/test/transactions.py
+++ b/Lib/sqlite3/test/transactions.py
@@ -118,13 +118,8 @@ class TransactionTests(unittest.TestCase):
             return
         self.cur1.execute("create table test(i)")
         self.cur1.execute("insert into test(i) values (5)")
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             self.cur2.execute("insert into test(i) values (5)")
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError:
-            pass
-        except:
-            self.fail("should have raised an OperationalError")
 
     def CheckLocking(self):
         """
@@ -137,13 +132,8 @@ class TransactionTests(unittest.TestCase):
             return
         self.cur1.execute("create table test(i)")
         self.cur1.execute("insert into test(i) values (5)")
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             self.cur2.execute("insert into test(i) values (5)")
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError:
-            pass
-        except:
-            self.fail("should have raised an OperationalError")
         # NO self.con2.rollback() HERE!!!
         self.con1.commit()
 
@@ -159,13 +149,8 @@ class TransactionTests(unittest.TestCase):
         cur.execute("select 1 union select 2 union select 3")
 
         con.rollback()
-        try:
+        with self.assertRaises(sqlite.InterfaceError):
             cur.fetchall()
-            self.fail("InterfaceError should have been raised")
-        except sqlite.InterfaceError as e:
-            pass
-        except:
-            self.fail("InterfaceError should have been raised")
 
 class SpecialCommandTests(unittest.TestCase):
     def setUp(self):
diff --git a/Lib/sqlite3/test/types.py b/Lib/sqlite3/test/types.py
index adad571..f7c8f9c 100644
--- a/Lib/sqlite3/test/types.py
+++ b/Lib/sqlite3/test/types.py
@@ -185,24 +185,14 @@ class DeclTypesTests(unittest.TestCase):
     def CheckUnsupportedSeq(self):
         class Bar: pass
         val = Bar()
-        try:
+        with self.assertRaises(sqlite.InterfaceError):
             self.cur.execute("insert into test(f) values (?)", (val,))
-            self.fail("should have raised an InterfaceError")
-        except sqlite.InterfaceError:
-            pass
-        except:
-            self.fail("should have raised an InterfaceError")
 
     def CheckUnsupportedDict(self):
         class Bar: pass
         val = Bar()
-        try:
+        with self.assertRaises(sqlite.InterfaceError):
             self.cur.execute("insert into test(f) values (:val)", {"val": val})
-            self.fail("should have raised an InterfaceError")
-        except sqlite.InterfaceError:
-            pass
-        except:
-            self.fail("should have raised an InterfaceError")
 
     def CheckBlob(self):
         # default
diff --git a/Lib/sqlite3/test/userfunctions.py b/Lib/sqlite3/test/userfunctions.py
index 8a4bbab..4075045 100644
--- a/Lib/sqlite3/test/userfunctions.py
+++ b/Lib/sqlite3/test/userfunctions.py
@@ -162,11 +162,8 @@ class FunctionTests(unittest.TestCase):
         self.con.close()
 
     def CheckFuncErrorOnCreate(self):
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             self.con.create_function("bla", -100, lambda x: 2*x)
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError:
-            pass
 
     def CheckFuncRefCount(self):
         def getfunc():
@@ -231,12 +228,10 @@ class FunctionTests(unittest.TestCase):
 
     def CheckFuncException(self):
         cur = self.con.cursor()
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             cur.execute("select raiseexception()")
             cur.fetchone()
-            self.fail("should have raised OperationalError")
-        except sqlite.OperationalError as e:
-            self.assertEqual(e.args[0], 'user-defined function raised exception')
+        self.assertEqual(str(cm.exception), 'user-defined function raised exception')
 
     def CheckParamString(self):
         cur = self.con.cursor()
@@ -312,55 +307,42 @@ class AggregateTests(unittest.TestCase):
         pass
 
     def CheckAggrErrorOnCreate(self):
-        try:
+        with self.assertRaises(sqlite.OperationalError):
             self.con.create_function("bla", -100, AggrSum)
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError:
-            pass
 
     def CheckAggrNoStep(self):
         cur = self.con.cursor()
-        try:
+        with self.assertRaises(AttributeError) as cm:
             cur.execute("select nostep(t) from test")
-            self.fail("should have raised an AttributeError")
-        except AttributeError as e:
-            self.assertEqual(e.args[0], "'AggrNoStep' object has no attribute 'step'")
+        self.assertEqual(str(cm.exception), "'AggrNoStep' object has no attribute 'step'")
 
     def CheckAggrNoFinalize(self):
         cur = self.con.cursor()
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             cur.execute("select nofinalize(t) from test")
             val = cur.fetchone()[0]
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError as e:
-            self.assertEqual(e.args[0], "user-defined aggregate's 'finalize' method raised error")
+        self.assertEqual(str(cm.exception), "user-defined aggregate's 'finalize' method raised error")
 
     def CheckAggrExceptionInInit(self):
         cur = self.con.cursor()
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             cur.execute("select excInit(t) from test")
             val = cur.fetchone()[0]
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError as e:
-            self.assertEqual(e.args[0], "user-defined aggregate's '__init__' method raised error")
+        self.assertEqual(str(cm.exception), "user-defined aggregate's '__init__' method raised error")
 
     def CheckAggrExceptionInStep(self):
         cur = self.con.cursor()
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             cur.execute("select excStep(t) from test")
             val = cur.fetchone()[0]
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError as e:
-            self.assertEqual(e.args[0], "user-defined aggregate's 'step' method raised error")
+        self.assertEqual(str(cm.exception), "user-defined aggregate's 'step' method raised error")
 
     def CheckAggrExceptionInFinalize(self):
         cur = self.con.cursor()
-        try:
+        with self.assertRaises(sqlite.OperationalError) as cm:
             cur.execute("select excFinalize(t) from test")
             val = cur.fetchone()[0]
-            self.fail("should have raised an OperationalError")
-        except sqlite.OperationalError as e:
-            self.assertEqual(e.args[0], "user-defined aggregate's 'finalize' method raised error")
+        self.assertEqual(str(cm.exception), "user-defined aggregate's 'finalize' method raised error")
 
     def CheckAggrCheckParamStr(self):
         cur = self.con.cursor()
@@ -433,22 +415,14 @@ class AuthorizerTests(unittest.TestCase):
         pass
 
     def test_table_access(self):
-        try:
+        with self.assertRaises(sqlite.DatabaseError) as cm:
             self.con.execute("select * from t2")
-        except sqlite.DatabaseError as e:
-            if not e.args[0].endswith("prohibited"):
-                self.fail("wrong exception text: %s" % e.args[0])
-            return
-        self.fail("should have raised an exception due to missing privileges")
+        self.assertIn('prohibited', str(cm.exception))
 
     def test_column_access(self):
-        try:
+        with self.assertRaises(sqlite.DatabaseError) as cm:
             self.con.execute("select c2 from t1")
-        except sqlite.DatabaseError as e:
-            if not e.args[0].endswith("prohibited"):
-                self.fail("wrong exception text: %s" % e.args[0])
-            return
-        self.fail("should have raised an exception due to missing privileges")
+        self.assertIn('prohibited', str(cm.exception))
 
 class AuthorizerRaiseExceptionTests(AuthorizerTests):
     @staticmethod