table.drop(ignore=True) option, refs #237

docs/python-api.rst

@@ -1026,6 +1026,12 @@ You can drop a table or view using the ``.drop()`` method:
 
     db["my_table"].drop()
 
+Pass ``ignore=True`` if you want to ignore the error caused by the table or view not existing.
+
+.. code-block:: python
+
+    db["my_table"].drop(ignore=True)
+
 .. _python_api_transform:
 
 Transforming a table

sqlite_utils/db.py

@@ -1212,8 +1212,12 @@ def add_column(
             self.add_foreign_key(col_name, fk, fk_col)
         return self
 
-    def drop(self):
-        self.db.execute("DROP TABLE [{}]".format(self.name))
+    def drop(self, ignore=False):
+        try:
+            self.db.execute("DROP TABLE [{}]".format(self.name))
+        except sqlite3.OperationalError:
+            if not ignore:
+                raise
 
     def guess_foreign_table(self, column):
         column = column.lower()
@@ -2195,8 +2199,12 @@ def __repr__(self):
             self.name, ", ".join(c.name for c in self.columns)
         )
 
-    def drop(self):
-        self.db.execute("DROP VIEW [{}]".format(self.name))
+    def drop(self, ignore=False):
+        try:
+            self.db.execute("DROP VIEW [{}]".format(self.name))
+        except sqlite3.OperationalError:
+            if not ignore:
+                raise
 
     def enable_fts(self, *args, **kwargs):
         raise NotImplementedError(

tests/test_create.py

@@ -6,6 +6,7 @@
     NoObviousTable,
     ForeignKey,
     Table,
+    View,
 )
 from sqlite_utils.utils import sqlite3
 import collections
@@ -944,6 +945,21 @@ def test_drop_view(fresh_db):
     assert [] == fresh_db.view_names()
 
 
+def test_drop_ignore(fresh_db):
+    with pytest.raises(sqlite3.OperationalError):
+        fresh_db["does_not_exist"].drop()
+    fresh_db["does_not_exist"].drop(ignore=True)
+    # Testing view is harder, we need to create it in order
+    # to get a View object, then drop it twice
+    fresh_db.create_view("foo_view", "select 1")
+    view = fresh_db["foo_view"]
+    assert isinstance(view, View)
+    view.drop()
+    with pytest.raises(sqlite3.OperationalError):
+        view.drop()
+    view.drop(ignore=True)
+
+
 def test_insert_all_empty_list(fresh_db):
     fresh_db["t"].insert({"foo": 1})
     assert 1 == fresh_db["t"].count

tests/test_extract.py

@@ -28,7 +28,9 @@ def test_extract_single_column(fresh_db, table, fk_column):
         "   [name] TEXT,\n"
         "   [{}] INTEGER,\n".format(expected_fk)
         + "   [end] INTEGER,\n"
-        + "   FOREIGN KEY([{}]) REFERENCES [{}]([id])\n".format(expected_fk, expected_table)
+        + "   FOREIGN KEY([{}]) REFERENCES [{}]([id])\n".format(
+            expected_fk, expected_table
+        )
         + ")"
     )
     assert fresh_db[expected_table].schema == (