Show a warning when the number of rows changes across populations

Author: NicholasMamo

examples/.ipynb_checkpoints/5. Bar charts-checkpoint.ipynb

@@ -9,6 +9,7 @@
 from numbers import Number
 import os
 import sys
+import warnings
 
 sys.path.append(os.path.join(os.path.abspath(os.path.dirname(__file__)), '..'))
 import util
@@ -36,6 +37,8 @@ class Population(LabelledVisualization):
     :ivar populations: A list of populations, represented as scatter points.
                        Each population contains these points, separated by column.
     :vartype populations: list of list of list of :class:`matplotlib.collections.PathCollection`
+    :ivar rows: The number of rows in the populations.
+    :vartype rows: int
     """
 
     def __init__(self, *args, **kwargs):
@@ -95,6 +98,12 @@ def draw(self, population, rows, name, style_plot=True, height=0.6,
         :raise ValueError: If the height is not between 0 and 1.
         """
 
+        # check that the number of rows is the same as in previous populations.
+        if self.rows and rows != self.rows:
+            warnings.warn(f"The number of rows is different between populations, changed from { self.rows } to { rows }")
+            self.rows = rows
+        self.rows = self.rows or rows
+
         # draw a general label
         if label:
             self._draw_legend(label, label_style, *args, **kwargs)

examples/.ipynb_checkpoints/7. Population charts-checkpoint.ipynb

@@ -143,6 +143,69 @@ def test_draw_large_height(self):
         viz = drawable.Drawable(plt.figure(figsize=(10, 10)))
         self.assertRaises(ValueError, viz.draw_population, 5, 10, '', height=2)
 
+    @MultiplexTest.temporary_plot
+    def test_draw_save_rows_first_time(self):
+        """
+        Test that when drawing a population the first time, the number of rows are saved in the class.
+        """
+
+        viz = drawable.Drawable(plt.figure(figsize=(10, 10)))
+        rows = 10
+        pop = viz.draw_population(5, rows, '', height=1)
+        self.assertEqual(rows, viz.population.rows)
+
+    @MultiplexTest.temporary_plot
+    def test_draw_save_rows_second_time(self):
+        """
+        Test that when drawing a population the second time, the number of rows are unchanged in the class.
+        """
+
+        viz = drawable.Drawable(plt.figure(figsize=(10, 10)))
+        rows = 10
+
+        # draw the first population
+        pop = viz.draw_population(5, rows, '', height=1)
+        self.assertEqual(rows, viz.population.rows)
+
+        # draw the second population
+        pop = viz.draw_population(5, rows, '', height=1)
+        self.assertEqual(rows, viz.population.rows)
+
+    @MultiplexTest.temporary_plot
+    def test_draw_save_rows_different(self):
+        """
+        Test that when drawing a population with a different number of rows than before, the class raises a warning.
+        """
+
+        viz = drawable.Drawable(plt.figure(figsize=(10, 10)))
+        rows = 10
+
+        # draw the first population
+        pop = viz.draw_population(5, rows, '', height=1)
+        self.assertEqual(rows, viz.population.rows)
+
+        # draw the second population
+        with self.assertWarns(Warning):
+            pop = viz.draw_population(5, rows - 1, '', height=1)
+
+    @MultiplexTest.temporary_plot
+    def test_draw_save_rows_different_update(self):
+        """
+        Test that when drawing a population with a different number of rows than before, the class saves the new number of rows after raising a warning.
+        """
+
+        viz = drawable.Drawable(plt.figure(figsize=(10, 10)))
+        rows = 10
+
+        # draw the first population
+        pop = viz.draw_population(5, rows, '', height=1)
+        self.assertEqual(rows, viz.population.rows)
+
+        # draw the second population
+        with self.assertWarns(Warning):
+            pop = viz.draw_population(5, rows - 1, '', height=1)
+            self.assertEqual(rows - 1, viz.population.rows)
+
     @MultiplexTest.temporary_plot
     def test_draw_save_population(self):
         """