fsspec: Remove botocore as a module import

In case you don't have `botocore` installed.

Author: Fokko

pyiceberg/io/fsspec.py

@@ -23,6 +23,7 @@
 from copy import copy
 from functools import lru_cache, partial
 from typing import (
+    TYPE_CHECKING,
     Any,
     Callable,
     Dict,
@@ -31,8 +32,6 @@
 from urllib.parse import urlparse
 
 import requests
-from botocore import UNSIGNED
-from botocore.awsrequest import AWSRequest
 from fsspec import AbstractFileSystem
 from fsspec.implementations.local import LocalFileSystem
 from requests import HTTPError
@@ -83,8 +82,11 @@
 
 logger = logging.getLogger(__name__)
 
+if TYPE_CHECKING:
+    from botocore.awsrequest import AWSRequest
 
-def s3v4_rest_signer(properties: Properties, request: AWSRequest, **_: Any) -> AWSRequest:
+
+def s3v4_rest_signer(properties: Properties, request: "AWSRequest", **_: Any) -> "AWSRequest":
     signer_url = properties.get(S3_SIGNER_URI, properties["uri"]).rstrip("/")
     signer_endpoint = properties.get(S3_SIGNER_ENDPOINT, S3_SIGNER_ENDPOINT_DEFAULT)
 
@@ -114,7 +116,7 @@ def s3v4_rest_signer(properties: Properties, request: AWSRequest, **_: Any) -> A
     return request
 
 
-SIGNERS: Dict[str, Callable[[Properties, AWSRequest], AWSRequest]] = {"S3V4RestSigner": s3v4_rest_signer}
+SIGNERS: Dict[str, Callable[[Properties, "AWSRequest"], "AWSRequest"]] = {"S3V4RestSigner": s3v4_rest_signer}
 
 
 def _file(_: Properties) -> LocalFileSystem:
@@ -141,6 +143,8 @@ def _s3(properties: Properties) -> AbstractFileSystem:
             register_events["before-sign.s3"] = signer_func_with_properties
 
             # Disable the AWS Signer
+            from botocore import UNSIGNED
+
             config_kwargs["signature_version"] = UNSIGNED
         else:
             raise ValueError(f"Signer not available: {signer}")