added use of ABC to mark TextGenerator as abstract

Author: ronanstokes-db

dbldatagen/text_generators.py

@@ -10,6 +10,7 @@
 import random
 
 import logging
+from abc import ABC, abstractmethod
 import numpy as np
 import pandas as pd
 
@@ -61,7 +62,7 @@
                 'LABORUM']
 
 
-class TextGenerator(object):
+class TextGenerator(ABC):
     """ Base class for text generation classes
 
     """
@@ -161,6 +162,10 @@ def getAsTupleOrElse(v, defaultValue, valueName):
 
         return defaultValue
 
+    @abstractmethod
+    def pandasGenerateText(self, v):
+        raise NotImplementedError("Subclasses should implement unique versions of `pandasGenerateText`")
+
 
 class TemplateGenerator(TextGenerator):  # lgtm [py/missing-equals]
     """This class handles the generation of text from templates

tests/test_text_generation.py

@@ -1,9 +1,9 @@
 import re
-import pytest
-import pandas as pd
-import numpy as np
 
+import numpy as np
+import pandas as pd
 import pyspark.sql.functions as F
+import pytest
 from pyspark.sql.types import BooleanType, DateType
 from pyspark.sql.types import StructType, StructField, IntegerType, StringType, TimestampType
 
@@ -44,9 +44,13 @@ class TestTextGeneration:
     row_count = 100000
     partitions_requested = 4
 
+    class TestTextGenerator(TextGenerator):
+        def pandasGenerateText(self, v):  # pylint: disable=useless-parent-delegation
+            return super().pandasGenerateText(v)
+
     def test_text_generator_basics(self):
         # test the random humber generator
-        tg1 = TextGenerator()
+        tg1 = self.TestTextGenerator()
 
         # test the repr
         desc = repr(tg1)

tests/test_text_generator_basic.py

@@ -1,7 +1,8 @@
 import re
-import pytest
+
 import numpy as np
 import pandas as pd
+import pytest
 
 from dbldatagen import TextGenerator, TemplateGenerator
 
@@ -12,10 +13,14 @@ class TestTextGeneratorBasic:
     row_count = 100000
     partitions_requested = 4
 
+    class TestTextGenerator(TextGenerator):
+        def pandasGenerateText(self, v):    # pylint: disable=useless-parent-delegation
+            return super().pandasGenerateText(v)
+
     @pytest.mark.parametrize("randomSeed", [None, 0, -1, 2112, 42])
     def test_text_generator_basic(self, randomSeed):
-        text_gen1 = TextGenerator()
-        text_gen2 = TextGenerator()
+        text_gen1 = self.TestTextGenerator()
+        text_gen2 = self.TestTextGenerator()
 
         if randomSeed is not None:
             text_gen1 = text_gen1.withRandomSeed(randomSeed)
@@ -29,14 +34,19 @@ def test_text_generator_basic(self, randomSeed):
 
         assert text_gen1 == text_gen2
 
+    def test_base_textgenerator_raises_error(self):
+        with pytest.raises(NotImplementedError):
+            text_gen1 = self.TestTextGenerator()
+            text_gen1.pandasGenerateText(None)
+
     @pytest.mark.parametrize("randomSeed, forceNewInstance", [(None, True), (None, False),
                                                               (0, True), (0, False),
                                                               (-1, True), (-1, False),
                                                               (2112, True), (2112, False),
                                                               (42, True), (42, False)])
     def test_text_generator_rng(self, randomSeed, forceNewInstance):
-        text_gen1 = TextGenerator()
-        text_gen2 = TextGenerator()
+        text_gen1 = self.TestTextGenerator()
+        text_gen2 = self.TestTextGenerator()
 
         if randomSeed is not None:
             text_gen1 = text_gen1.withRandomSeed(randomSeed)
@@ -71,7 +81,7 @@ def test_text_generator_rng(self, randomSeed, forceNewInstance):
                                                       (np.array([1, 40000.4, 3]), np.uint16)
                                                       ])
     def test_text_generator_compact_types(self, values, expectedType):
-        text_gen1 = TextGenerator()
+        text_gen1 = self.TestTextGenerator()
 
         np_type = text_gen1.compactNumpyTypeForValues(values)
         assert np_type == expectedType