Fix duckdb#26. (duckdb#31)

This hopefully fixes duckdb#26:

- Changed the type of the file_globs parameter of from_parquet and
read_parquet in connection_methods.json.
- Added the generation of @overload functions in the generation wrappers
python code.

Author: evertlammerts

scripts/connection_methods.json

@@ -412,7 +412,7 @@
 			"fetch_record_batch",
 			"arrow"
 		],
-		
+
 		"function": "FetchRecordBatchReader",
 		"docs": "Fetch an Arrow RecordBatchReader following execute()",
 		"args": [
@@ -992,7 +992,7 @@
 		"args": [
 			{
 				"name": "file_globs",
-				"type": "str"
+				"type": "List[str]"
 			},
 			{
 				"name": "binary_as_string",

scripts/generate_connection_stubs.py

@@ -51,8 +51,12 @@ def create_arguments(arguments) -> list:
             result.append(argument)
         return result
 
-    def create_definition(name, method) -> str:
-        definition = f"def {name}("
+    def create_definition(name, method, overloaded: bool) -> str:
+        if overloaded:
+            definition: str = "@overload\n"
+        else:
+            definition: str = ""
+        definition += f"def {name}("
         arguments = ['self']
         if 'args' in method:
             arguments.extend(create_arguments(method['args']))
@@ -65,20 +69,17 @@ def create_definition(name, method) -> str:
         definition += f" -> {method['return']}: ..."
         return definition
 
-    # We have "duplicate" methods, which are overloaded
-    # maybe we should add @overload to these instead, but this is easier
-    written_methods = set()
+    # We have "duplicate" methods, which are overloaded.
+    # We keep note of them to add the @overload decorator.
+    overloaded_methods: set[str] = {m for m in connection_methods if isinstance(m['name'], list)}
 
     for method in connection_methods:
         if isinstance(method['name'], list):
             names = method['name']
         else:
             names = [method['name']]
         for name in names:
-            if name in written_methods:
-                continue
-            body.append(create_definition(name, method))
-            written_methods.add(name)
+            body.append(create_definition(name, method, name in overloaded_methods))
 
     # ---- End of generation code ----
 

scripts/generate_connection_wrapper_stubs.py

@@ -66,8 +66,12 @@ def create_arguments(arguments) -> list:
             result.append(argument)
         return result
 
-    def create_definition(name, method) -> str:
-        definition = f"def {name}("
+    def create_definition(name, method, overloaded: bool) -> str:
+        if overloaded:
+            definition: str = "@overload\n"
+        else:
+            definition: str = ""
+        definition += f"def {name}("
         arguments = []
         if name in SPECIAL_METHOD_NAMES:
             arguments.append('df: pandas.DataFrame')
@@ -82,9 +86,9 @@ def create_definition(name, method) -> str:
         definition += f" -> {method['return']}: ..."
         return definition
 
-    # We have "duplicate" methods, which are overloaded
-    # maybe we should add @overload to these instead, but this is easier
-    written_methods = set()
+    # We have "duplicate" methods, which are overloaded.
+    # We keep note of them to add the @overload decorator.
+    overloaded_methods: set[str] = {m for m in connection_methods if isinstance(m['name'], list)}
 
     body = []
     for method in methods:
@@ -99,10 +103,7 @@ def create_definition(name, method) -> str:
         method['kwargs'].append({'name': 'connection', 'type': 'DuckDBPyConnection', 'default': '...'})
 
         for name in names:
-            if name in written_methods:
-                continue
-            body.append(create_definition(name, method))
-            written_methods.add(name)
+            body.append(create_definition(name, method, name in overloaded_methods))
 
     # ---- End of generation code ----