Nit: Introduce S3_SIGNER constant property (#1837)

Author: smaheshwar-pltr

pyiceberg/io/__init__.py

@@ -63,6 +63,7 @@
 S3_PROXY_URI = "s3.proxy-uri"
 S3_CONNECT_TIMEOUT = "s3.connect-timeout"
 S3_REQUEST_TIMEOUT = "s3.request-timeout"
+S3_SIGNER = "s3.signer"
 S3_SIGNER_URI = "s3.signer.uri"
 S3_SIGNER_ENDPOINT = "s3.signer.endpoint"
 S3_SIGNER_ENDPOINT_DEFAULT = "v1/aws/s3/sign"

pyiceberg/io/fsspec.py

@@ -67,6 +67,7 @@
     S3_REQUEST_TIMEOUT,
     S3_SECRET_ACCESS_KEY,
     S3_SESSION_TOKEN,
+    S3_SIGNER,
     S3_SIGNER_ENDPOINT,
     S3_SIGNER_ENDPOINT_DEFAULT,
     S3_SIGNER_URI,
@@ -137,7 +138,7 @@ def _s3(properties: Properties) -> AbstractFileSystem:
     config_kwargs = {}
     register_events: Dict[str, Callable[[Properties], None]] = {}
 
-    if signer := properties.get("s3.signer"):
+    if signer := properties.get(S3_SIGNER):
         logger.info("Loading signer %s", signer)
         if signer_func := SIGNERS.get(signer):
             signer_func_with_properties = partial(signer_func, properties)