bite 110

Author: boraxpr

110/division.py

@@ -0,0 +1,18 @@
+def divide_numbers(numerator, denominator):
+    """For this exercise you can assume numerator and denominator are of type
+       int/str/float.
+       Try to convert numerator and denominator to int types, if that raises a
+       ValueError reraise it. Following do the division and return the result.
+       However if denominator is 0 catch the corresponding exception Python
+       throws (cannot divide by 0), and return 0"""
+    try:
+        numerator = int(numerator)
+        denominator = int(denominator)
+    except ValueError:
+        raise ValueError
+    try:
+        return numerator/denominator
+    except ZeroDivisionError:
+        return 0
+
+# divide_numbers(1,0)

110/test_division.py

@@ -0,0 +1,36 @@
+import pytest
+
+from division import divide_numbers
+
+
+@pytest.mark.parametrize("numerator, denominator, expected", [
+    (1, 2, 0.5),
+    (8, 2, 4),
+    # strings that look like ints are converted (casted) fine
+    ('3', '2', 1.5),
+    # floats work too but when casted to int they are rounded down!
+    (8.2, 2, 4),
+    (1, 2.9, 0.5),
+])
+def test_divide_numbers_good_inputs(numerator, denominator, expected):
+    assert divide_numbers(numerator, denominator) == expected
+
+
+@pytest.mark.parametrize("numerator, denominator", [
+    # ignoring dict/set/list to keep it simple, those would actually
+    # throw a TypeError when passed into int()
+    (2, 's'),
+    ('s', 2),
+    ('v', 'w'),
+])
+def test_divide_numbers_raises_value_error(numerator, denominator):
+    with pytest.raises(ValueError):
+        divide_numbers(numerator, denominator)
+
+
+def test_divide_by_zero_does_not_raise_zero_division_exception():
+    assert divide_numbers(10, 0) == 0
+
+test_divide_by_zero_does_not_raise_zero_division_exception()
+test_divide_numbers_good_inputs
+test_divide_numbers_raises_value_error