bite 230 - Operator overloading - Object Oriented

Author: boraxpr

.gitignore

@@ -1,3 +1,4 @@
+*.md
 *.txt
 *.html
 .idea/

230/test_thumbs.py

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+import pytest
+
+from thumbs import Thumbs
+
+
+@pytest.fixture(scope="module")
+def thumbs():
+    return Thumbs()
+
+
+@pytest.mark.parametrize("arg, expected", [
+    (-10, "👎 (10x)"),
+    (-9, "👎 (9x)"),
+    (-8, "👎 (8x)"),
+    (-7, "👎 (7x)"),
+    (-6, "👎 (6x)"),
+    (-5, "👎 (5x)"),
+    (-4, "👎 (4x)"),
+    (-3, "👎👎👎"),
+    (-2, "👎👎"),
+    (-1, "👎"),
+    (1, "👍"),
+    (2, "👍👍"),
+    (3, "👍👍👍"),
+    (4, "👍 (4x)"),
+    (5, "👍 (5x)"),
+    (6, "👍 (6x)"),
+    (7, "👍 (7x)"),
+    (8, "👍 (8x)"),
+    (9, "👍 (9x)"),
+    (10, "👍 (10x)"),
+])
+def test_operator_overloading_works_both_ways(arg, expected, thumbs):
+    assert thumbs * arg == arg * thumbs == expected
+
+
+def test_exception(thumbs):
+    with pytest.raises(ValueError):
+        thumbs * 0
+    with pytest.raises(ValueError):
+        0 * thumbs

230/thumbs.py

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+THUMBS_UP, THUMBS_DOWN = '👍', '👎'
+
+
+def emoji_multiply(multiplier):
+    if multiplier == 0:
+        raise ValueError("Specify a number")
+    thumb = THUMBS_UP
+    if multiplier < 0:
+        thumb = THUMBS_DOWN
+    multiplier = abs(multiplier)
+    if multiplier in [1, 2, 3]:
+        return thumb * multiplier
+    else:
+        return str(thumb) + " ({}x)".format(multiplier)
+
+
+class Thumbs:
+    def __mul__(self, multiplier):
+        return emoji_multiply(multiplier)
+
+    def __rmul__(self, multiplier):
+        return emoji_multiply(multiplier)