From 7e4b9997c2cec4c2af42bd3088847a81c970b6fc Mon Sep 17 00:00:00 2001
From: Simon Willison <swillison@gmail.com>
Date: Sun, 12 Apr 2020 20:46:51 -0700
Subject: [PATCH] Database(..., recreate=True) option, refs #97

---
 docs/python-api.rst | 10 +++++++++-
 sqlite_utils/db.py  | 12 +++++++-----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/docs/python-api.rst b/docs/python-api.rst
index 1b2a2c5..310fb01 100644
--- a/docs/python-api.rst
+++ b/docs/python-api.rst
@@ -15,7 +15,15 @@ Database objects are constructed by passing in either a path to a file on disk o
 
     db = Database("my_database.db")
 
-This will create ``my_database.db`` if it does not already exist. You can also pass in an existing SQLite connection:
+This will create ``my_database.db`` if it does not already exist.
+
+If you want to recreate a database from scratch (first removing the existing file from disk if it already exists) you can use the ``recreate=True`` argument:
+
+.. code-block:: python
+
+    db = Database("my_database.db", recreate=True)
+
+Instead of a file path you can pass in an existing SQLite connection:
 
 .. code-block:: python
 
diff --git a/sqlite_utils/db.py b/sqlite_utils/db.py
index d51ede3..3f9bb6f 100644
--- a/sqlite_utils/db.py
+++ b/sqlite_utils/db.py
@@ -4,6 +4,7 @@ import datetime
 import hashlib
 import itertools
 import json
+import os
 import pathlib
 
 SQLITE_MAX_VARS = 999
@@ -96,17 +97,18 @@ class PrimaryKeyRequired(Exception):
 
 
 class Database:
-    def __init__(self, filename_or_conn=None, memory=False):
+    def __init__(self, filename_or_conn=None, memory=False, recreate=False):
         assert (filename_or_conn is not None and not memory) or (
             filename_or_conn is None and memory
         ), "Either specify a filename_or_conn or pass memory=True"
-        if memory:
+        if memory or filename_or_conn == ":memory:":
             self.conn = sqlite3.connect(":memory:")
-        elif isinstance(filename_or_conn, str):
-            self.conn = sqlite3.connect(filename_or_conn)
-        elif isinstance(filename_or_conn, pathlib.Path):
+        elif isinstance(filename_or_conn, (str, pathlib.Path)):
+            if recreate and os.path.exists(filename_or_conn):
+                os.remove(filename_or_conn)
             self.conn = sqlite3.connect(str(filename_or_conn))
         else:
+            assert not recreate, "recreate cannot be used with connections, only paths"
             self.conn = filename_or_conn
 
     def __getitem__(self, table_name):