Homework 1 Submission - Nik Andrews (andre223)

fib-fn.py

@@ -2,11 +2,11 @@
 last_2 = 1
 
 def next():
-    global last_1, last_2
+    global last_1, last_2  #use the global last_1 and last_2
 
-    next_fib = last_1 + last_2
-    last_1, last_2 = last_2, next_fib
-
+    next_fib = last_1 + last_2   #store the sum of last_1 and last_2 
+    last_1, last_2 = last_2, next_fib    #re-assignment of the variables.
+                     # last_1 = last_2 && last_2 = next_fib 
     return next_fib
 
 print next()

fib_gen/example.py

@@ -3,5 +3,7 @@
 for n, i in zip(range(3), fib.fib()):
     print i
 
+print type(fib.fib())
+
 # additional questions to address:
 # - what the heck do 'zip' and 'range' do, and why are they there?

fib_gen/fib.py

@@ -2,16 +2,21 @@
 # a generator.
 
 def fib():
-    last_1 = 1
+    last_1 = 1 # stored locally in this function
     last_2 = 1
 
     while 1:
-        next_fib = last_1 + last_2
-        last_1, last_2 = last_2, next_fib
-        yield next_fib
+       # next_fib = last_1 + last_2
+
+       # yield next_fib
+       yield (last_1 + last_2)
+       # last_1, last_2 = last_2, next_fib
+       last_1, last_2 = last_2, (last_1+last_2)
 
 # additional questions to address:
 # - could you swap the last two lines of the while statement?  what are the
 #    plusses and minuses of doing so?
+
+
 # - is there a way to condense the 'while' loop into two statements? try
 #    getting rid of the next_fib variable.

fib_iter/example.py

@@ -1,7 +1,11 @@
 import fib
 
-for n, i in zip(range(3), fib.fib()):
-    print i
+for n, i in zip(range(5), fib.fib()):  # Gets the returned value of __iter__ 
+    print n, i
 
 # additional questions to address:
 # - what the heck do 'zip' and 'range' do, and why are they there?
+'''	'zip' returns a list of tuples, where the ith tuple contains the 
+	ith element for each argument sequences of iterables. 
+	'range' is a function that contains iterator progressions. In this 
+	example the iterator starts at 0 and ends at 2. '''	

iter_bug/fib.py

@@ -12,5 +12,5 @@ def __iter__(self):
 
     def next(self):
         next_fib = self.last_1 + self.last_2
-        self.last_1, self.last2 = self.last_2, next_fib
+        self.last_1, self.last_2 = self.last_2, next_fib
         return next_fib

iter_bug/test.py

@@ -11,13 +11,14 @@ def test2():
     i.next()
     assert i.next() == 3
 
-def test2():
+def test3():
     f = fib.fib()
     i = iter(f)
     i.next()
     i.next()
     assert i.next() == 5
 
+# Tests
 test1()
 test2()
 test3()

series-fn.py

@@ -1,4 +1,4 @@
-n = 0
+n = 0  # 1. n is set to 0.
 
 def add_one():
     global n

series_gen/series.py

@@ -3,6 +3,6 @@
 
 def adder():
     n = 0
-    while 1:
-        n += 1
-        yield n
+    while 1:  # while true
+        n += 1 
+        yield n # returns generated n

series_mod/series.py

@@ -1,13 +1,17 @@
 # this is an implementation of the 'series' functionality using a module.
 
-n = 0
+n = 0 # Sets n to 0
 
 def add_one():
-    global n
-    n = n + 1
+    global n  # Sets a global n, init value 0. 
+    n = n + 1 # increment n by 1
     return n
 
 # additional questions to address:
 #  - what does 'global' do, above?
+#	Uses the n thats defined locally and uses it as a global variable.
+
 #  - what naming limitations are there on series.py? Could we name it
 #        series_mod.py or series-mod.py, and still have it work as a module?
+
+#	As long as the correct

sieve_gen/example.py

@@ -0,0 +1,6 @@
+import sieve
+
+for n, i in zip(range(10), sieve.next()):
+    print i
+
+

sieve_gen/sieve.py

@@ -0,0 +1,17 @@
+_primeslist = [2]
+
+def _is_prime(primes, n):
+    for i in primes:
+        if n % i == 0:
+            return False
+    return True
+
+def next():
+    start = _primeslist[-1] + 1
+    while 1:
+        if _is_prime(_primeslist, start):
+            _primeslist.append(start)
+            yield start
+        start+=1
+
+

sieve_gen/test1.py

@@ -0,0 +1,8 @@
+import sieve
+
+def test1():    
+    s = sieve.next()    
+    i = iter(s)    
+    assert i.next() == 3 
+
+test1()

sieve_gen/test2.py

@@ -0,0 +1,12 @@
+import sieve
+
+def test2():
+    s = sieve.next()
+    i = iter(s)
+
+    for x in range(4):
+	i.next()
+
+    assert i.next() == 13
+
+test2()

sieve_gen/test3.py

@@ -0,0 +1,12 @@
+import sieve
+
+def test3():    
+    s = sieve.next()    
+    i = iter(s)    
+
+    for x in range(8):        
+	i.next()    
+    assert i.next() == 29
+
+
+test3()

sieve_iter/example.py

@@ -0,0 +1,7 @@
+import sieve
+
+for n, i in zip(range(10),sieve.sieve()):
+    print i
+
+
+

sieve_iter/sieve.py

@@ -0,0 +1,28 @@
+# Implementation using iter
+
+class sieve(object):
+    def __init__(self):
+	self._primeslist = [2]
+
+    def __iter__(self):
+	return self
+
+    def _is_prime(self, n):
+	for i in self._primeslist:
+	    if(n % i == 0):
+		return False
+	return True
+
+
+    def next(self):
+	start = self._primeslist[-1] + 1
+	while 1:
+	    if self._is_prime(start):
+		self._primeslist.append(start)
+		return start
+
+	    start+=1
+
+
+
+

sieve_iter/test1.py

@@ -0,0 +1,8 @@
+import sieve
+
+def test1():    
+    s = sieve.sieve()    
+    i = iter(s)    
+    assert i.next() == 3
+
+test1()

sieve_iter/test2.py

@@ -0,0 +1,11 @@
+import sieve
+
+def test2():    
+    s = sieve.sieve()    
+    i = iter(s)    
+
+    for x in range(4):        
+	i.next()    
+    assert i.next() == 13
+
+test2()

sieve_iter/test3.py

@@ -0,0 +1,11 @@
+import sieve
+
+def test3():    
+    s = sieve.sieve()    
+    i = iter(s)    
+
+    for x in range(8):        
+	i.next()    
+    assert i.next() == 29
+
+test3()

sieve_mod/example.py

@@ -0,0 +1,7 @@
+import sieve
+
+for n in range(10):
+    print sieve.next()
+
+
+

sieve_mod/sieve.py

@@ -0,0 +1,18 @@
+_primeslist = [2]
+
+def _is_prime(primes, n):
+    for i in primes:
+        if n % i == 0:
+            return False
+    return True
+
+def next():
+    start = _primeslist[-1] + 1
+    while 1:
+        if _is_prime(_primeslist, start):
+            _primeslist.append(start)
+            return start
+
+        start += 1
+
+