Add exception handling

app/api/views/upload/dataset.py

@@ -1,11 +1,11 @@
 import csv
 import json
-from itertools import chain
 from typing import Dict, Iterator, List, Optional, Type
 
 import pyexcel
 
 from .data import BaseData
+from .exception import FileParseException
 from .label import Label
 from .labels import Labels
 
@@ -25,32 +25,20 @@ class Record:
 
     @property
     def data(self):
-        return self._data
-
-    @property
-    def annotation(self):
-        return Labels(self._label)
-
-    @property
-    def label(self):
-        return [label.name for label in self._label if label.has_name() and label.name]
-
-
-class Records:
-
-    def __init__(self, records: List[Record]):
-        self.records = records
-
-    def data(self):
-        return [r.data.dict() for r in self.records]
+        return self._data.dict()
 
     def annotation(self, mapping: Dict[str, int]):
-        return [r.annotation.replace_label(mapping).dict() for r in self.records]
+        labels = Labels(self._label)
+        labels = labels.replace_label(mapping)
+        return labels.dict()
 
+    @property
     def label(self):
-        labels = set(chain(*[r.label for r in self.records]))
         return [
-            {'text': label} for label in labels
+            {
+                'text': label.name
+            } for label in self._label
+            if label.has_name() and label.name
         ]
 
 
@@ -72,15 +60,6 @@ class Dataset:
         for filename in self.filenames:
             yield from self.load(filename)
 
-    def batch(self, batch_size) -> Records:
-        records = []
-        for record in self:
-            records.append(record)
-            if len(records) == batch_size:
-                yield Records(records)
-                records = []
-        yield Records(records)
-
     def load(self, filename: str) -> Iterator[Record]:
         """Loads a file content."""
         with open(filename, encoding=self.encoding) as f:
@@ -88,7 +67,11 @@ class Dataset:
             record = Record(data=data)
             yield record
 
-    def from_row(self, filename: str, row: Dict) -> Record:
+    def from_row(self, filename: str, row: Dict, line_num: int) -> Record:
+        column_data = self.kwargs.get('column_data', 'text')
+        if column_data not in row:
+            message = f'{column_data} does not exist.'
+            raise FileParseException(filename, line_num, message)
         text = row.pop(self.kwargs.get('column_data', 'text'))
         label = row.pop(self.kwargs.get('column_label', 'label'), [])
         label = [label] if isinstance(label, str) else label
@@ -132,9 +115,15 @@ class CsvDataset(Dataset):
             delimiter = self.kwargs.get('delimiter', ',')
             reader = csv.reader(f, delimiter=delimiter)
             header = next(reader)
-            for row in reader:
+
+            column_data = self.kwargs.get('column_data', 'text')
+            if column_data not in header:
+                message = f'{column_data} does not exist in the header: {header}'
+                raise FileParseException(filename, 1, message)
+
+            for line_num, row in enumerate(reader, start=2):
                 row = dict(zip(header, row))
-                yield self.from_row(filename, row)
+                yield self.from_row(filename, row, line_num)
 
 
 class JSONDataset(Dataset):
@@ -142,36 +131,39 @@ class JSONDataset(Dataset):
     def load(self, filename: str) -> Iterator[Record]:
         with open(filename, encoding=self.encoding) as f:
             dataset = json.load(f)
-            for row in dataset:
-                yield self.from_row(filename, row)
+            for line_num, row in enumerate(dataset, start=1):
+                yield self.from_row(filename, row, line_num)
 
 
 class JSONLDataset(Dataset):
 
     def load(self, filename: str) -> Iterator[Record]:
         with open(filename, encoding=self.encoding) as f:
-            for line in f:
+            for line_num, line in enumerate(f, start=1):
                 row = json.loads(line)
-                yield self.from_row(filename, row)
+                yield self.from_row(filename, row, line_num)
 
 
 class ExcelDataset(Dataset):
 
     def load(self, filename: str) -> Iterator[Record]:
         records = pyexcel.iget_records(filename)
-        for row in records:
-            yield self.from_row(filename, row)
+        for line_num, row in enumerate(records, start=1):
+            yield self.from_row(filename, row, line_num)
 
 
 class FastTextDataset(Dataset):
 
     def load(self, filename: str) -> Iterator[Record]:
         with open(filename, encoding=self.encoding) as f:
-            for i, line in enumerate(f, start=1):
+            for line_num, line in enumerate(f, start=1):
                 labels = []
                 tokens = []
                 for token in line.rstrip().split(' '):
                     if token.startswith('__label__'):
+                        if token == '__label__':
+                            message = 'Label name is empty.'
+                            raise FileParseException(filename, line_num, message)
                         label_name = token[len('__label__'):]
                         labels.append(self.label_class.parse(label_name))
                     else: