Merge pull request #50 from scrapinghub/feat-append-extend

New Functionalities: append and extend

shublang/shublang.py

@@ -87,6 +87,35 @@ def format(iterable, template):
     return (template.format(*x) for x in iterable)
 
 
+@Pipe
+def append(iterable, data):
+    """Appends data to the iterable.
+
+    :param iterable: collection of data to transform
+    :type iterable: list
+
+    :param data: any type of data to be appended
+    """
+
+    iterable.append(data)
+    return iterable
+
+
+@Pipe
+def extend(iterable, extension):
+    """Extends the iterable using another iterable.
+
+    :param iterable: collection of data to transform
+    :type iterable: list
+
+    :param extension: contains the additional iterable to extend the current one
+    :param extension: iterable
+    """
+
+    iterable.extend(extension)
+    return iterable
+
+
 @Pipe
 def encode(iterable, encoding, errors='ignore'):
     return (x.encode(encoding, errors=errors) for x in iterable)

tests/test_functions.py

@@ -61,25 +61,21 @@ def test_replace(test_input, expected):
             ['format("Now Playing: {} and {}")', [['Rick', 'Morty']]],
             ['Now Playing: Rick and Morty']
         ),
-
         # Ordering should be respected
         (
             ['format("{2}, {1}, and {0}")', [['a', 'b', 'c']]],
             ['c, b, and a']
         ),
-
         # Lists of lists are aggregated into a list
         (
             ['format("{} and some value {}")', [[1, 2], ['x', 'y']]],
             ['1 and some value 2', 'x and some value y']
         ),
-
         # Args could be repeated
         (
             ['format("{0}--{0}-{1}!")', [['Re', 'Remix']]],
             ['Re--Re-Remix!']
         ),
-
         # Standard Formatting should work
         (
             ['format("{:.2f}")', [[7/3]]],
@@ -91,6 +87,56 @@ def test_format(test_input, expected):
     assert evaluate(*test_input) == expected
 
 
+@pytest.mark.parametrize(
+    "test_input,expected",
+    [
+        (
+            ['append("new thing")', ['A', 'B']],
+            ['A', 'B', 'new thing']
+        ),
+        # list could be added as a single item
+        (
+            ['append([1, 2, "3"])', ['A', 'B']],
+            ['A', 'B', [1, 2, '3']]
+        ),
+    ]
+)
+def test_append(test_input, expected):
+    assert evaluate(*test_input) == expected
+
+
+@pytest.mark.parametrize(
+    "test_input,expected",
+    [
+        (
+            ['extend([1, 2, "3"])', ['A', 'B']],
+            ['A', 'B', 1, 2, '3']
+        ),
+
+        # generators will also work
+        (
+            ['extend(range(3, 6))', ['A', 'B']],
+            ['A', 'B', 3, 4, 5]
+        ),
+
+        # single strings are treated as iterables
+        (
+            ['extend("new")', ['A', 'B']],
+            ['A', 'B', 'n', 'e', 'w']
+        ),
+    ]
+)
+def test_extend(test_input, expected):
+    assert evaluate(*test_input) == expected
+
+
+def test_extend_with_non_iterable():
+    """It should raise a TypeError."""
+
+    with pytest.raises(TypeError):
+        evaluate("extend(123)", ['A', 'B'])
+
+
 def test_encode():
     text = "ἀἐἠἰὀὐὠὰᾀᾐ"
     assert evaluate('encode("UTF8")', data=[text]) ==\
@@ -110,7 +156,7 @@ def test_decode():
             ['split(",")', ['Python,Haskell,Scala,Rust']],
             [['Python', 'Haskell', 'Scala', 'Rust']]
         ),
-        
+
         # maxsplit should limit the number of separations
         (
             ['split(",", 2)', ['Python,Haskell,Scala,Rust']],