Merge branch 'main' into impl3

README.md

@@ -11,6 +11,12 @@ In this course, we assume familiarity with the following Git commands and GitHub
 If these are new to you then please join the
 [*Introduction to Git and GitHub for Beginners* course][1], which is running in parallel.
 
+## Accompanying slides
+
+Please click
+[here](https://hackmd.io/@jwallwork/2024-07-10-intermediate-git-tools?type=slide#/)
+to access to the accompanying slides.
+
 ## The example code
 
 This repository contains example code in a Python module `maths.py`. This module

maths.py

@@ -1,4 +1,5 @@
 from sympy import Line, Point2D
+import numpy as np
 
 
 def equation_of_line(a, b):
@@ -9,6 +10,8 @@ def equation_of_line(a, b):
     :arg b: the second point the line passes through
     :return: function of two variables defining the line
     """
+    if np.allclose(a, b):
+        raise ValueError("Cannot determine a unique line through {a} and {b}.")
     line = Line(Point2D(a), Point2D(b))
 
     def evaluate(x, y):

test_maths.py

@@ -17,3 +17,8 @@ def test_equation(a, b, condition):
         iszero = np.isclose(f(x, y), 0)
         if (not iszero if condition(x, y) else iszero):
             raise AssertionError(f"f({x},{y}) {'!=' if condition(x, y) else '=='} 0")
+
+
+def test_single_point():
+    with pytest.raises(ValueError):
+        equation_of_line((0, 0), (0, 0))