Merge pull request UWPCE-PythonCert#86 from voite1/master

Homework 8 complete

Author: PythonCHB

Students/A.Kramer/session08/generator_solution.py

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+'''
+Created on Nov 26, 2014
+
+@author: Alekesey Kramer
+'''
+
+# Generator to add numbers to predecessors
+def intsum():
+    num = 0
+    count = 0
+    while num >= 0:
+        yield num
+        count += 1
+        num += count
+
+
+def doubler():
+    num = 1
+    while num >= 0:
+        yield num
+        num = num*2
+        
+def prime():
+    # My code :-)
+    count = 2
+    while True:
+        if __is_prime(count):
+            yield count
+            count += 1
+        else:
+            count += 1
+
+# Found this code on the web at 
+# https://www.daniweb.com/software-development/python/threads/70650/an-isprimen-function
+# with combination from here: http://stackoverflow.com/questions/15285534/isprime-function-for-python-language
+# and modified a bit to reject all the numbers lees than 2 (just in case I will use it later)
+# quite useful and fast function, but limited by the have the size of int...
+def __is_prime(n):
+    if n < 2:
+        return False
+    if n == 2:
+        return True
+    # checking only odd numbers
+    for x in range(3, int(n**0.5)+1, 2):
+        if n % x == 0:
+            return False
+    return True
+
+# fibonacci
+def fib():
+    first = 1
+    second = 1
+    while True:
+        yield(first)
+        n = first + second
+        first = second
+        second = n
+
+
+if __name__ == "__main__":
+    print "Sum of integers"
+    sum_of_ints = intsum()
+    print sum_of_ints.next()
+    print sum_of_ints.next()
+    print sum_of_ints.next()
+    print sum_of_ints.next()
+    print sum_of_ints.next()
+    print sum_of_ints.next()
+    print
+    print "Doubler"
+    doub = doubler()
+    print doub.next()
+    print doub.next()
+    print doub.next()
+    print doub.next()
+    print doub.next()
+    print doub.next()
+    print
+    print "Getting Primes"
+    g = prime()
+    print g.next()
+    print g.next()
+    print g.next()
+    print g.next()
+    print g.next()
+    print g.next()
+    print g.next()
+    print g.next()
+    print g.next()
+    print
+    print "Fibonacci"
+    f = fib()
+    print f.next()
+    print f.next()
+    print f.next()
+    print f.next()
+    print f.next()
+    print f.next()
+    print f.next()
+    print f.next()
+    print f.next()
+
+
+
+
+

Students/A.Kramer/session08/quadratic.py

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+'''
+Created on Nov 25, 2014
+
+@author: Aleksey
+'''
+
+# Quadratic equation
+class Quadratic(object):
+    def __init__(self, a, b, c):
+        self._a = a
+        self._b = b
+        self._c = c
+    
+    def __call__(self, x):
+        self._x = x
+        return self._a * self._x**2 + self._b * self._x + self._c
+
+
+if __name__ == "__main__":
+    q = Quadratic(1,2,3)
+    print q(3)

Students/A.Kramer/session08/sparse_array.py

@@ -0,0 +1,33 @@
+class SparseArray(object):
+    def __init__(self, iterable):
+        self.values = {}
+        self.length = len(iterable)
+        for i, val in enumerate(iterable):
+            if val:
+                self.values[i] = val
+        
+    def __getitem__(self, index):
+        if index >= self.length:
+            raise IndexError("Sparse array index out of range")
+        else:
+            return self.values.get(index, 0)
+    
+    def __setitem__(self, index, value):
+        if index >= self.length:
+            raise IndexError("Sparse array index out of range")
+        else:
+            if value == 0:
+                self.values.pop(index, None)
+            else:
+                self.values[index] = value
+    
+    def __delitem__(self, index):
+        if index >= self.length:
+            raise IndexError("Sparse array index out of range")
+        else:
+            self.values.pop(index, None)
+            self.length -= 1
+            
+    def __len__(self):
+        return self.length
+    

Students/A.Kramer/session08/test_generator.py

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+"""
+test_generator.py
+
+tests the solution to the generator lab
+
+can be run with py.test or nosetests
+"""
+
+import generator_solution as gen 
+
+
+def test_intsum():
+
+    g = gen.intsum() 
+
+    assert g.next() == 0
+    assert g.next() == 1
+    assert g.next() == 3
+    assert g.next() == 6
+    assert g.next() == 10
+    assert g.next() == 15
+
+
+def test_doubler():
+
+    g = gen.doubler()
+
+    assert g.next() == 1
+    assert g.next() == 2
+    assert g.next() == 4
+    assert g.next() == 8
+    assert g.next() == 16
+    assert g.next() == 32
+
+    for i in range(10):
+        j = g.next()
+
+    assert j == 2**15
+
+
+def test_fib():
+    g = gen.fib()
+
+    assert g.next() == 1
+    assert g.next() == 1
+    assert g.next() == 2
+    assert g.next() == 3
+    assert g.next() == 5
+    assert g.next() == 8
+    assert g.next() == 13
+    assert g.next() == 21
+
+
+def test_prime():
+    g = gen.prime()
+
+    assert g.next() == 2
+    assert g.next() == 3
+    assert g.next() == 5
+    assert g.next() == 7
+    assert g.next() == 11
+    assert g.next() == 13
+    assert g.next() == 17
+    assert g.next() == 19
+    assert g.next() == 23

Students/A.Kramer/session08/test_quadratic.py

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+#!/usr/bin/env python
+
+"""
+test code for the quadratic function evaluator
+"""
+
+import pytest
+
+from quadratic import Quadratic
+
+
+def test_init(): 
+    q = Quadratic(1,2,3)
+
+
+def test_evaluate():
+    q = Quadratic(1,2,3)
+
+    assert q(3) == 9 + 6 + 3
+    assert q(0) == 3
+
+
+def test_evaluate2():
+    q = Quadratic(2,1,-3)
+
+    assert q(0) == -3
+    assert q(1) == 2 + 1 - 3
+    assert q(-2) == 8 - 2 - 3
+
+
+def test_bad_input():
+
+    with pytest.raises(TypeError):
+        q = Quadratic(2,3)
+

Students/A.Kramer/session08/test_sparse_array.py

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+import pytest
+from sparse_array import SparseArray 
+
+
+def set_up():
+    my_array = [2, 0, 0, 0, 3, 0, 0, 0, 4, 5, 6, 0, 2, 9]
+    my_sparse = SparseArray(my_array)
+    return (my_array, my_sparse)
+
+
+def test_object_exists():
+    my_array, my_sparse = set_up()
+    assert isinstance(my_sparse, SparseArray)
+
+def test_get_non_zero_number():
+    my_array, my_sparse = set_up()
+    assert my_sparse[4] == 3
+
+def test_get_zero():
+    my_array, my_sparse = set_up()
+    assert my_sparse[1] == 0
+
+def test_get_element_not_in_array():
+    my_array, my_sparse = set_up()
+    with pytest.raises(IndexError):
+        my_sparse[14]
+
+def test_get_lenght():
+    my_array, my_sparse = set_up()
+    assert len(my_sparse) == 14
+
+def test_change_number_in_array():
+    my_array, my_sparse = set_up()
+    my_sparse[0] = 3
+    assert my_sparse[0] == 3
+    # make sure others aren't changed
+    assert my_sparse[1] == 0
+    # make sure still same length
+    assert len(my_sparse) == 14
+
+def test_change_number_in_array_to_zero():
+    my_array, my_sparse = set_up()
+    my_sparse[4] = 0
+    assert my_sparse[4] == 0
+    # make sure still same length
+    assert len(my_sparse) == 14
+
+def test_change_number_in_array_from_zero():
+    my_array, my_sparse = set_up()
+    my_sparse[1] = 4
+    assert my_sparse[1] == 4
+    # make sure still same length
+    assert len(my_sparse) == 14
+
+def test_delete_number():
+    my_array, my_sparse = set_up()
+    del(my_sparse[4])
+    # if we delete the 4 position, should now be zero
+    assert my_sparse[4] == 0
+    # should have smaller length
+    assert len(my_sparse) == 13
+
+
+def test_delete_zero():
+    my_array, my_sparse = set_up()
+    del(my_sparse[5])
+    # should still be zero, but should have shorter length
+    assert my_sparse[5] == 0
+    assert len(my_sparse) == 13
+
+def test_delete_last_number():
+    my_array, my_sparse = set_up()
+    del(my_sparse[13])
+    # should get an error?
+    print 'print some stuff damnit'
+    with pytest.raises(IndexError):
+        my_sparse[13]
+    assert len(my_sparse) == 13
+
+
+
+