Delete the first-defined (and thus "duplicate") Script class

The second definition was copied over the first definition,
with the following changes:

* The type annotations were copied to the second definition
* The mutable default arguments to the `keys` and `args` parameters
  were replaced with `None`, as is best-practice.

Closes #3332

Author: kurtmckee

CHANGES

@@ -66,6 +66,7 @@
     * Prevent async ClusterPipeline instances from becoming "false-y" in case of empty command stack (#3061)
     * Close Unix sockets if the connection attempt fails. This prevents `ResourceWarning`s. (#3314)
     * Close SSL sockets if the connection attempt fails, or if validations fail. (#3317)
+    * Eliminate mutable default arguments in the `redis.commands.core.Script` class. (#3332)
 
 * 4.1.3 (Feb 8, 2022)
   * Fix flushdb and flushall (#1926)

redis/commands/core.py

@@ -5472,11 +5472,7 @@ def __init__(self, registered_client: "Redis", script: ScriptTextT):
         if isinstance(script, str):
             # We need the encoding from the client in order to generate an
             # accurate byte representation of the script
-            try:
-                encoder = registered_client.connection_pool.get_encoder()
-            except AttributeError:
-                # Cluster
-                encoder = registered_client.get_encoder()
+            encoder = self.get_encoder()
             script = encoder.encode(script)
         self.sha = hashlib.sha1(script).hexdigest()
 
@@ -5507,6 +5503,24 @@ def __call__(
             self.sha = client.script_load(self.script)
             return client.evalsha(self.sha, len(keys), *args)
 
+    def get_encoder(self):
+        """Get the encoder to encode string scripts into bytes."""
+        try:
+            return self.registered_client.get_encoder()
+        except AttributeError:
+            # DEPRECATED
+            # In version <=4.1.2, this was the code we used to get the encoder.
+            # However, after 4.1.2 we added support for scripting in clustered
+            # redis. ClusteredRedis doesn't have a `.connection_pool` attribute
+            # so we changed the Script class to use
+            # `self.registered_client.get_encoder` (see above).
+            # However, that is technically a breaking change, as consumers who
+            # use Scripts directly might inject a `registered_client` that
+            # doesn't have a `.get_encoder` field. This try/except prevents us
+            # from breaking backward-compatibility. Ideally, it would be
+            # removed in the next major release.
+            return self.registered_client.connection_pool.get_encoder()
+
 
 class AsyncScript:
     """
@@ -6283,62 +6297,6 @@ def command(self) -> ResponseT:
         return self.execute_command("COMMAND")
 
 
-class Script:
-    """
-    An executable Lua script object returned by ``register_script``
-    """
-
-    def __init__(self, registered_client, script):
-        self.registered_client = registered_client
-        self.script = script
-        # Precalculate and store the SHA1 hex digest of the script.
-
-        if isinstance(script, str):
-            # We need the encoding from the client in order to generate an
-            # accurate byte representation of the script
-            encoder = self.get_encoder()
-            script = encoder.encode(script)
-        self.sha = hashlib.sha1(script).hexdigest()
-
-    def __call__(self, keys=[], args=[], client=None):
-        "Execute the script, passing any required ``args``"
-        if client is None:
-            client = self.registered_client
-        args = tuple(keys) + tuple(args)
-        # make sure the Redis server knows about the script
-        from redis.client import Pipeline
-
-        if isinstance(client, Pipeline):
-            # Make sure the pipeline can register the script before executing.
-            client.scripts.add(self)
-        try:
-            return client.evalsha(self.sha, len(keys), *args)
-        except NoScriptError:
-            # Maybe the client is pointed to a different server than the client
-            # that created this instance?
-            # Overwrite the sha just in case there was a discrepancy.
-            self.sha = client.script_load(self.script)
-            return client.evalsha(self.sha, len(keys), *args)
-
-    def get_encoder(self):
-        """Get the encoder to encode string scripts into bytes."""
-        try:
-            return self.registered_client.get_encoder()
-        except AttributeError:
-            # DEPRECATED
-            # In version <=4.1.2, this was the code we used to get the encoder.
-            # However, after 4.1.2 we added support for scripting in clustered
-            # redis. ClusteredRedis doesn't have a `.connection_pool` attribute
-            # so we changed the Script class to use
-            # `self.registered_client.get_encoder` (see above).
-            # However, that is technically a breaking change, as consumers who
-            # use Scripts directly might inject a `registered_client` that
-            # doesn't have a `.get_encoder` field. This try/except prevents us
-            # from breaking backward-compatibility. Ideally, it would be
-            # removed in the next major release.
-            return self.registered_client.connection_pool.get_encoder()
-
-
 class AsyncModuleCommands(ModuleCommands):
     async def command_info(self) -> None:
         return super().command_info()