[Typing][B-61] Add type annotations for python/paddle/text/datasets/imdb.py (PaddlePaddle#66037)

---------

Co-authored-by: Nyakku Shigure <[email protected]>

Author: 2 people

python/paddle/text/datasets/imdb.py

@@ -11,17 +11,25 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from __future__ import annotations
 
 import collections
 import re
 import string
 import tarfile
+from typing import TYPE_CHECKING, Literal
 
 import numpy as np
 
 from paddle.dataset.common import _check_exists_and_download
 from paddle.io import Dataset
 
+if TYPE_CHECKING:
+    from re import Pattern
+
+    import numpy.typing as npt
+
+    _ImdbDataSetMode = Literal["train", "test"]
 __all__ = []
 
 URL = 'https://dataset.bj.bcebos.com/imdb%2FaclImdb_v1.tar.gz'
@@ -33,12 +41,12 @@ class Imdb(Dataset):
     Implementation of `IMDB <https://www.imdb.com/interfaces/>`_ dataset.
 
     Args:
-        data_file(str): path to data tar file, can be set None if
-            :attr:`download` is True. Default None
+        data_file(str|None): path to data tar file, can be set None if
+            :attr:`download` is True. Default None.
         mode(str): 'train' 'test' mode. Default 'train'.
         cutoff(int): cutoff number for building word dictionary. Default 150.
         download(bool): whether to download dataset automatically if
-            :attr:`data_file` is not set. Default True
+            :attr:`data_file` is not set. Default True.
 
     Returns:
         Dataset: instance of IMDB dataset
@@ -82,7 +90,19 @@ class Imdb(Dataset):
 
     """
 
-    def __init__(self, data_file=None, mode='train', cutoff=150, download=True):
+    data_file: str | None
+    mode: _ImdbDataSetMode
+    word_idx: dict[str, int]
+    docs: list
+    labels: list
+
+    def __init__(
+        self,
+        data_file: str | None = None,
+        mode: _ImdbDataSetMode = 'train',
+        cutoff: int = 150,
+        download: bool = True,
+    ) -> None:
         assert mode.lower() in [
             'train',
             'test',
@@ -104,7 +124,7 @@ def __init__(self, data_file=None, mode='train', cutoff=150, download=True):
         # read dataset into memory
         self._load_anno()
 
-    def _build_work_dict(self, cutoff):
+    def _build_work_dict(self, cutoff: int) -> dict[str, int]:
         word_freq = collections.defaultdict(int)
         pattern = re.compile(r"aclImdb/((train)|(test))/((pos)|(neg))/.*\.txt$")
         for doc in self._tokenize(pattern):
@@ -120,7 +140,7 @@ def _build_work_dict(self, cutoff):
         word_idx['<unk>'] = len(words)
         return word_idx
 
-    def _tokenize(self, pattern):
+    def _tokenize(self, pattern: Pattern[str]) -> list[list[str]]:
         data = []
         with tarfile.open(self.data_file) as tarf:
             tf = tarf.next()
@@ -139,7 +159,7 @@ def _tokenize(self, pattern):
 
         return data
 
-    def _load_anno(self):
+    def _load_anno(self) -> None:
         pos_pattern = re.compile(fr"aclImdb/{self.mode}/pos/.*\.txt$")
         neg_pattern = re.compile(fr"aclImdb/{self.mode}/neg/.*\.txt$")
 
@@ -154,8 +174,10 @@ def _load_anno(self):
             self.docs.append([self.word_idx.get(w, UNK) for w in doc])
             self.labels.append(1)
 
-    def __getitem__(self, idx):
+    def __getitem__(
+        self, idx: int
+    ) -> tuple[npt.NDArray[np.int_], npt.NDArray[np.int_]]:
         return (np.array(self.docs[idx]), np.array([self.labels[idx]]))
 
-    def __len__(self):
+    def __len__(self) -> int:
         return len(self.docs)