Update README.md

README.md

@@ -7,32 +7,22 @@ __import__('concurrent').futures.ThreadPoolExecutor().submit(
 ## sqlite3
 ```py
 def SQL():
-   def File(blob):
-      try: import zmq; File.sock.send_pyobj(blob); return File.sock.recv_pyobj()
-      except (AttributeError, zmq.Again):
-         (sock := zmq.Context().socket(zmq.REQ)).connect('tcp://localhost:6106')
-         sock.RCVTIMEO = 1000; File.sock = sock; return File(blob)
-
-    import sqlite3
+    def File(blob):
+        try: import zmq; File.sock.send_pyobj(blob); return File.sock.recv_pyobj()
+        except (AttributeError, zmq.Again):
+            (sock := zmq.Context().socket(zmq.REQ)).connect('tcp://localhost:6106')
+            sock.RCVTIMEO = 1000; File.sock = sock; return File(blob)
+    import sqlite3, os; init = not os.path.exists('.db')
     (con := sqlite3.connect('.db', isolation_level=None)).row_factory = sqlite3.Row
-    con.executescript("""
+    if init: con.executescript("""
         PRAGMA journal_mode=WAL;
-        CREATE TABLE IF NOT EXISTS kv(k, v, t DEFAULT CURRENT_TIMESTAMP);
-        CREATE INDEX IF NOT EXISTS index_kv_v ON kv(v);
-        CREATE INDEX IF NOT EXISTS index_kv_k_t ON kv(k, t DESC);
-    """)
-    def setitem(sql, filename, blob):
-        assert isinstance(blob, bytes)
-        sql('INSERT INTO kv(k, v) VALUES(?,?)', filename, File(blob))
-    def getitem(sql, filename):
-        if sha1 := sql('SELECT v FROM kv WHERE k=? ORDER BY t DESC', filename):
-            return File(sha1[0]['v'])
-    def contains(sql, filename):
-        return bool(sql('SELECT 1 FROM kv WHERE k=?', filename))
-    def df(sql):
-        import pandas as pd
-        return pd.DataFrame(sql('SELECT * FROM kv'))
+        CREATE TABLE kv(k, v, t DEFAULT CURRENT_TIMESTAMP);
+        CREATE INDEX index_kv_v ON kv(v);
+        CREATE INDEX index_kv_k_t ON kv(k, t DESC);""")
     return type('', (), dict(__call__=lambda _, q, *p: list(map(dict, con.execute(q, p))),
-        __setitem__=setitem, __getitem__=getitem, __contains__=contains, df=df))()
+        __setitem__=lambda sql, k, v: sql('INSERT INTO kv(k,v) VALUES(?,?)', k, File(v)),
+        __getitem__=lambda sql, k: File(v[0]['v']) if (v := sql(
+            'SELECT v FROM kv WHERE k=? ORDER BY t DESC LIMIT 1', k)) else None,
+        __contains__=lambda sql, k: bool(sql('SELECT 1 FROM kv WHERE k=?', k))))()
 sql = SQL()
 ```