Support basic completion for sqlite3 command-line interface

Author: tanloong

Lib/sqlite3/__main__.py

@@ -9,6 +9,7 @@
 
 from argparse import ArgumentParser
 from code import InteractiveConsole
+from contextlib import contextmanager
 from textwrap import dedent
 
 
@@ -62,6 +63,59 @@ def runsource(self, source, filename="<input>", symbol="single"):
         return False
 
 
+def _complete(text, state):
+    keywords = ["ABORT", "ACTION", "ADD", "AFTER", "ALL", "ALTER", "ALWAYS",
+                "ANALYZE", "AND", "AS", "ASC", "ATTACH", "AUTOINCREMENT",
+                "BEFORE", "BEGIN", "BETWEEN", "BY", "CASCADE", "CASE", "CAST",
+                "CHECK", "COLLATE", "COLUMN", "COMMIT", "CONFLICT",
+                "CONSTRAINT", "CREATE", "CROSS", "CURRENT", "CURRENT_DATE",
+                "CURRENT_TIME", "CURRENT_TIMESTAMP", "DATABASE", "DEFAULT",
+                "DEFERRABLE", "DEFERRED", "DELETE", "DESC", "DETACH",
+                "DISTINCT", "DO", "DROP", "EACH", "ELSE", "END", "ESCAPE",
+                "EXCEPT", "EXCLUDE", "EXCLUSIVE", "EXISTS", "EXPLAIN", "FAIL",
+                "FILTER", "FIRST", "FOLLOWING", "FOR", "FOREIGN", "FROM",
+                "FULL", "GENERATED", "GLOB", "GROUP", "GROUPS", "HAVING", "IF",
+                "IGNORE", "IMMEDIATE", "IN", "INDEX", "INDEXED", "INITIALLY",
+                "INNER", "INSERT", "INSTEAD", "INTERSECT", "INTO", "IS",
+                "ISNULL", "JOIN", "KEY", "LAST", "LEFT", "LIKE", "LIMIT",
+                "MATCH", "MATERIALIZED", "NATURAL", "NO", "NOT", "NOTHING",
+                "NOTNULL", "NULL", "NULLS", "OF", "OFFSET", "ON", "OR",
+                "ORDER", "OTHERS", "OUTER", "OVER", "PARTITION", "PLAN",
+                "PRAGMA", "PRECEDING", "PRIMARY", "QUERY", "RAISE", "RANGE",
+                "RECURSIVE", "REFERENCES", "REGEXP", "REINDEX", "RELEASE",
+                "RENAME", "REPLACE", "RESTRICT", "RETURNING", "RIGHT",
+                "ROLLBACK", "ROW", "ROWS", "SAVEPOINT", "SELECT", "SET",
+                "TABLE", "TEMP", "TEMPORARY", "THEN", "TIES", "TO",
+                "TRANSACTION", "TRIGGER", "UNBOUNDED", "UNION", "UNIQUE",
+                "UPDATE", "USING", "VACUUM", "VALUES", "VIEW", "VIRTUAL",
+                "WHEN", "WHERE", "WINDOW", "WITH", "WITHOUT"]
+    options = [c + " " for c in keywords if c.startswith(text.upper())]
+    try:
+        return options[state]
+    except IndexError:
+        return None
+
+@contextmanager
+def _enable_completer():
+    try:
+        import readline
+    except ImportError:
+        yield
+        return
+
+    old_completer = readline.get_completer()
+    try:
+        readline.set_completer(_complete)
+        if readline.backend == "editline":
+            # libedit uses "^I" instead of "tab"
+            command_string = "bind ^I rl_complete"
+        else:
+            command_string = "tab: complete"
+        readline.parse_and_bind(command_string)
+        yield
+    finally:
+        readline.set_completer(old_completer)
+
 def main(*args):
     parser = ArgumentParser(
         description="Python sqlite3 CLI",
@@ -114,12 +168,9 @@ def main(*args):
             execute(con, args.sql, suppress_errors=False)
         else:
             # No SQL provided; start the REPL.
-            console = SqliteInteractiveConsole(con)
-            try:
-                import readline  # noqa: F401
-            except ImportError:
-                pass
-            console.interact(banner, exitmsg="")
+            with _enable_completer():
+                console = SqliteInteractiveConsole(con)
+                console.interact(banner, exitmsg="")
     finally:
         con.close()