Adds builtin function examples.

Author: paulross

Beginers/BuiltinFunctions/problem.py

@@ -0,0 +1,111 @@
+"""Builtin functions problems.
+It might be useful to browse here (adjust your version to suit):
+https://docs.python.org/2.7/library/functions.html
+
+1. Create the sequence [0, 3, 6, 9, ... N]. What is the problem if N is very large?
+Is there a better way if N is very large?
+
+2. Find the difference between the biggest and smallest values in the list
+[4, 3, -9, 21, 0]
+
+3. The same as 2. but use the absolute values in the list.
+
+4.Convert a list:
+['Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine']
+To a dictionary:
+{
+    0 : 'Zero',
+    1 : 'One',
+    2 : 'Two',
+    3 : 'Three',
+    4 : 'Four',
+    5 : 'Five',
+    6 : 'Six',
+    7 : 'Seven',
+    8 : 'Eight',
+    9 : 'Nine',
+}
+
+5. I have two list a and b. Is there a way that I can tell if they are the same
+list? For example in the following case they are the same list:
+a = [1, 2, 3]
+b = a
+And any change to b be will be 'seen' by a.
+However in this case a and b are not the same list in the sense that any change
+to b be will NOT be 'seen' by a. 
+a = [1, 2, 3]
+b = [1, 2, 3]
+
+Created on 22 Feb 2016
+
+@author: paulross
+"""
+import sys
+
+import pytest
+
+def create_sequence(N):
+    """Create the 3x table up to and including N."""
+    # Your code here
+    pass
+
+def range_of_list():
+    """Return the difference between the largest and smallest values in a list."""
+    x = [4, 3, -9, 21, 0]
+    # Your code here
+
+def range_of_list_abs():
+    """Return the difference between the largest and smallest absolute values in a list."""
+    x = [4, 3, -9, 21, 0]
+    # Your code here
+
+def list_to_sequence_dict():
+    """Create a dictionary where the key is the ordinal of the object in the list
+    and the value is the object itself. For example: {0 : 'Zero', 1 : 'One', ...}"""
+    x = ['Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine']
+    d = {}
+    # Your code here
+    return d
+
+def is_same(a, b):
+    """Return True is the two items are the same."""
+    # Your code here
+    pass
+
+#=========== Tests ===================
+def test_create_sequence():
+    assert create_sequence(12) == [0, 3, 6, 9, 12]
+    
+def test_range_of_list():
+    assert range_of_list() == 30
+
+def test_range_of_list_abs():
+    assert range_of_list_abs() == 21
+
+def test_list_to_sequence_dict():
+    expected = {
+        0 : 'Zero',
+        1 : 'One',
+        2 : 'Two',
+        3 : 'Three',
+        4 : 'Four',
+        5 : 'Five',
+        6 : 'Six',
+        7 : 'Seven',
+        8 : 'Eight',
+        9 : 'Nine',
+    }
+    assert list_to_sequence_dict() == expected
+
+def test_is_same():
+    a = [1, 2, 3]
+    b = a
+    assert is_same(a, b)
+    b = [1, 2, 3]
+    assert not is_same(a, b)
+    
+def main():
+    return pytest.main(__file__)
+
+if __name__ == '__main__':
+    sys.exit(main())

Beginers/BuiltinFunctions/solution.py

@@ -0,0 +1,113 @@
+"""Builtin functions problems.
+It might be useful to browse here (adjust your version to suit):
+https://docs.python.org/2.7/library/functions.html
+
+1. Create the sequence [0, 3, 6, 9, ... N]. What is the problem if N is very large?
+Is there a better way if N is very large?
+
+2. Find the difference between the biggest and smallest values in the list
+[4, 3, -9, 21, 0]
+
+3. The same as 2. but use the absolute values in the list.
+
+4.Convert a list:
+['Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine']
+To a dictionary:
+{
+    0 : 'Zero',
+    1 : 'One',
+    2 : 'Two',
+    3 : 'Three',
+    4 : 'Four',
+    5 : 'Five',
+    6 : 'Six',
+    7 : 'Seven',
+    8 : 'Eight',
+    9 : 'Nine',
+}
+
+5. I have two list a and b. Is there a way that I can tell if they are the same
+list? For example in the following case they are the same list:
+a = [1, 2, 3]
+b = a
+And any change to b be will be 'seen' by a.
+However in this case a and b are not the same list in the sense that any change
+to b be will NOT be 'seen' by a. 
+a = [1, 2, 3]
+b = [1, 2, 3]
+
+Created on 22 Feb 2016
+
+@author: paulross
+"""
+import sys
+
+import pytest
+
+def create_sequence(N):
+    """Create the 3x table up to and including N."""
+    return range(0, N + 3, 3)
+
+def range_of_list():
+    """Return the difference between the largest and smallest values in a list."""
+    x = [4, 3, -9, 21, 0]
+    return max(x) - min(x)
+
+def range_of_list_abs():
+    """Return the difference between the largest and smallest absolute values in a list."""
+    x = [4, 3, -9, 21, 0]
+    abs_x = [abs(value) for value in x]
+    return max(abs_x) - min(abs_x)
+
+def list_to_sequence_dict():
+    """Create a dictionary where the key is the ordinal of the object in the list
+    and the value is the object itself. For example: {0 : 'Zero', 1 : 'One', ...}"""
+    x = ['Zero', 'One', 'Two', 'Three', 'Four', 'Five', 'Six', 'Seven', 'Eight', 'Nine']
+    d = {}
+    for index, value in enumerate(x):
+        d[index] = value
+    return d
+
+def is_same(a, b):
+    """Return True is the two items are the same."""
+    # This is the same as:
+    # return a is b
+    return id(a) == id(b)
+
+#=========== Tests ===================
+def test_create_sequence():
+    assert create_sequence(12) == [0, 3, 6, 9, 12]
+    
+def test_range_of_list():
+    assert range_of_list() == 30
+
+def test_range_of_list_abs():
+    assert range_of_list_abs() == 21
+
+def test_list_to_sequence_dict():
+    expected = {
+        0 : 'Zero',
+        1 : 'One',
+        2 : 'Two',
+        3 : 'Three',
+        4 : 'Four',
+        5 : 'Five',
+        6 : 'Six',
+        7 : 'Seven',
+        8 : 'Eight',
+        9 : 'Nine',
+    }
+    assert list_to_sequence_dict() == expected
+
+def test_is_same():
+    a = [1, 2, 3]
+    b = a
+    assert is_same(a, b)
+    b = [1, 2, 3]
+    assert not is_same(a, b)
+    
+def main():
+    return pytest.main(__file__)
+
+if __name__ == '__main__':
+    sys.exit(main())