Minor attr -> dataclasses cleanup

PiperOrigin-RevId: 346958035

tensorflow_datasets/core/tfrecords_reader.py

@@ -384,8 +384,7 @@ def read_files(
        a tf.data.Dataset instance.
     """
     if not file_instructions:
-      msg = 'Instruction {} corresponds to no data!'.format(
-          file_instructions)
+      msg = f'Instruction {file_instructions} corresponds to no data!'
       raise AssertionError(msg)
 
     # Prepend path to filename

tensorflow_datasets/core/utils/shard_utils.py

@@ -21,39 +21,29 @@
  sharding needs.
 """
 
-from typing import List, Sequence
+from typing import Any, List, Sequence
 
-import attr
+import dataclasses
 
 
-@attr.s(frozen=True)
-class FileInstruction(object):  # TODO(epot): Uses dataclasses instead
+@dataclasses.dataclass(eq=True, frozen=True)
+class FileInstruction(object):
   """Instruction to read a single shard/file.
 
   Attributes:
     filename: The filenames contains the relative path, not absolute.
-    skip: Indicates which example read in the shard (`ds.skip().take()`). `None`
+    skip: Indicates which example read in the shard (`ds.skip().take()`). `0`
       if no skipping
-    take: Indicates how many examples to read (`None` to read all)
+    take: Indicates how many examples to read (`-1` to read all)
     num_examples: `int`, The total number of examples
   """
-  filename = attr.ib()
-  skip = attr.ib()
-  take = attr.ib()
-  num_examples = attr.ib()
+  filename: str
+  skip: int
+  take: int
+  num_examples: int
 
-  def asdict(self):
-    return {
-        'filename': self.filename,
-        'skip': self.skip,
-        'take': self.take,
-        'num_examples': self.num_examples,
-    }
-
-  def replace(self, **kwargs):
-    new_attrs = self.asdict()
-    new_attrs.update(kwargs)
-    return type(self)(**new_attrs)
+  def replace(self, **kwargs: Any) -> 'FileInstruction':
+    return dataclasses.replace(self, **kwargs)
 
 
 def get_file_instructions(