fix: support int for `parent_id` in `import_group`

This will also fix other use cases where an integer is passed in to
MultipartEncoder.

Added unit tests to show it works.

Closes: #2506

2 files changed, 10 insertions, 6 deletions

diff --git a/gitlab/_backends/requests_backend.py b/gitlab/_backends/requests_backend.py
index d70cf42..839b69e 100644
--- a/gitlab/_backends/requests_backend.py
+++ b/gitlab/_backends/requests_backend.py
@@ -70,17 +70,21 @@ class RequestsBackend(protocol.Backend):
             if post_data is None:
                 post_data = {}
             else:
-                # booleans does not exists for data (neither for MultipartEncoder):
-                # cast to string int to avoid: 'bool' object has no attribute 'encode'
+                # When creating a `MultipartEncoder` instance with data-types
+                # which don't have an `encode` method it will cause an error:
+                #       object has no attribute 'encode'
+                # So convert common non-string types into strings.
                 if TYPE_CHECKING:
                     assert isinstance(post_data, dict)
                 for k, v in post_data.items():
                     if isinstance(v, bool):
-                        post_data[k] = str(int(v))
+                        v = int(v)
+                    if isinstance(v, (complex, float, int)):
+                        post_data[k] = str(v)
             post_data["file"] = files.get("file")
             post_data["avatar"] = files.get("avatar")
 
-            data = MultipartEncoder(post_data)
+            data = MultipartEncoder(fields=post_data)
             return SendData(data=data, content_type=data.content_type)
 
         if raw and post_data:
diff --git a/gitlab/v4/objects/groups.py b/gitlab/v4/objects/groups.py
index 0eb516f..4dc4fd1 100644
--- a/gitlab/v4/objects/groups.py
+++ b/gitlab/v4/objects/groups.py
@@ -378,7 +378,7 @@ class GroupManager(CRUDMixin, RESTManager):
         file: BinaryIO,
         path: str,
         name: str,
-        parent_id: Optional[str] = None,
+        parent_id: Optional[Union[int, str]] = None,
         **kwargs: Any,
     ) -> Union[Dict[str, Any], requests.Response]:
         """Import a group from an archive file.
@@ -399,7 +399,7 @@ class GroupManager(CRUDMixin, RESTManager):
             A representation of the import status.
         """
         files = {"file": ("file.tar.gz", file, "application/octet-stream")}
-        data = {"path": path, "name": name}
+        data: Dict[str, Any] = {"path": path, "name": name}
         if parent_id is not None:
             data["parent_id"] = parent_id