Initial commit.

.gitignore

+.idea
+*.pyc
+*.pyo
+*.apk

examples.py

+# A function with associated doctests.
+def parse(pair):
+    """
+    Converts a key/value pair represented as a string to a key/value pair represented as a tuple.
+
+    Key/value pairs are expected to be separated by a colon and a space:
+    >>> parse('a key: a value')
+    ('a key', 'a value')
+
+    If there is no colon and space, parse raises a ValueError:
+    >>> parse('invalid')
+    Traceback (most recent call last):
+      ...
+    ValueError: need more than 1 value to unpack
+
+    Likewise if there is more than one separator:
+    >>> parse('first: second: third')
+    Traceback (most recent call last):
+      ...
+    ValueError: too many values to unpack (expected 2)
+    """
+    key, value = pair.split(': ')
+    return key, value
+

test_parse.py

+from unittest import TestCase
+import examples
+
+
+# The same tests in a separate unit-testing class.
+class TestParse(TestCase):
+    # assertEqual is like a reversed version of assertEquals from JUnit.
+    def test_parse(self):
+        self.assertEqual(examples.parse('a key: a value'), ('a key', 'a value'))
+
+    # It is also possible to expect exceptions like in the doctests, but the syntax is a little different.
+    def test_parse_single(self):
+        self.assertRaises(ValueError, examples.parse, 'invalid')
+
+    def test_parse_triple(self):
+        self.assertRaises(ValueError, examples.parse, 'first: second: third')