Fix two types of issues raised by mypy - implicit optional issues and…

… arg-type mismatch (#1234)

Summary:
Title. Here is the mypy run failing with 24 errors - https://github.com/pytorch/data/actions/runs/8428471909/job/23081016202.

With these two changes, the mypy errors are now down to 8 - https://github.com/pytorch/data/actions/runs/8428898766/job/23082258705?pr=1234

### Changes

- Add optional where it was implicit earlier
- Change ignore type to arg-type

Pull Request resolved: #1234

Reviewed By: ejguan

Differential Revision: D55350451

Pulled By: gokulavasan

fbshipit-source-id: 54a99c8879eaf84aea0fb833cbbd9f37bc504db9

torchdata/datapipes/iter/load/online.py

@@ -36,7 +36,7 @@ def _get_response_from_http(
 ) -> Tuple[str, StreamWrapper]:
     with requests.Session() as session:
         proxies = _get_proxies()
-        r = session.get(url, timeout=timeout, proxies=proxies, stream=True, **query_params)  # type: ignore[attr-defined]
+        r = session.get(url, timeout=timeout, proxies=proxies, stream=True, **query_params)  # type: ignore[arg-type]
     r.raise_for_status()
     return url, StreamWrapper(r.raw)
 
@@ -112,7 +112,7 @@ def _get_response_from_google_drive(
     confirm_token = None
 
     with requests.Session() as session:
-        response = session.get(url, timeout=timeout, stream=True, **query_params)  # type: ignore[attr-defined]
+        response = session.get(url, timeout=timeout, stream=True, **query_params)  # type: ignore[arg-type]
         response.raise_for_status()
 
         for k, v in response.cookies.items():
@@ -129,7 +129,7 @@ def _get_response_from_google_drive(
         if confirm_token:
             url = url + "&confirm=" + confirm_token
 
-        response = session.get(url, timeout=timeout, stream=True, **query_params)  # type: ignore[attr-defined]
+        response = session.get(url, timeout=timeout, stream=True, **query_params)  # type: ignore[arg-type]
         response.raise_for_status()
 
         if "content-disposition" not in response.headers:

torchdata/datapipes/iter/util/cacheholder.py

@@ -202,7 +202,7 @@ def __init__(
         self,
         source_datapipe: IterDataPipe,
         filepath_fn: Optional[Callable] = None,
-        hash_dict: Dict[str, str] = None,
+        hash_dict: Optional[Dict[str, str]] = None,
         hash_type: str = "sha256",
         extra_check_fn: Optional[Callable[[str], bool]] = None,
     ):

torchdata/datapipes/iter/util/rows2columnar.py

@@ -5,7 +5,7 @@
 # LICENSE file in the root directory of this source tree.
 
 from collections import defaultdict
-from typing import Dict, Iterator, List, Union
+from typing import Dict, Iterator, List, Optional, Union
 
 from torchdata.datapipes import functional_datapipe
 from torchdata.datapipes.iter import IterDataPipe
@@ -50,7 +50,9 @@ class Rows2ColumnarIterDataPipe(IterDataPipe[Dict]):
     """
     column_names: List[str]
 
-    def __init__(self, source_datapipe: IterDataPipe[List[Union[Dict, List]]], column_names: List[str] = None) -> None:
+    def __init__(
+        self, source_datapipe: IterDataPipe[List[Union[Dict, List]]], column_names: Optional[List[str]] = None
+    ) -> None:
         self.source_datapipe: IterDataPipe[List[Union[Dict, List]]] = source_datapipe
         self.column_names: List[str] = [] if column_names is None else column_names