Assignment 1 - 4

solutions/00-README.md

@@ -1,6 +1,6 @@
 # Solutions
-Place solutions in this directory as they become available.
+You can review these solutions as they become available and compare them to your own code. They are provided for comparison and do not directly determine your grade, but if your code is close to these examples, you are doing fine!
+
+- Please remember that these are just one way to do the exercies and may not even the best way. 
+
 
-Remember to document your solutions, preferably mentioning where
-students might get tripped up. None of the teachers, and none of the students,
-want to debug *your* code.

solutions/Lesson01/break_me.py

@@ -0,0 +1,36 @@
+#!/usr/bin/env python
+
+"""
+A simple set of examples that raise various Exceptions
+"""
+
+
+def name_error():
+    """This function raises a NameError"""
+    # very easy to do -- simply try to use a name you haven't defined
+    x = something
+
+
+def type_error():
+    """This function raises a TypeError"""
+    # Try to use an object in a way that doesn't make sense
+    "543" / 3
+
+def attribute_error():
+    """This function raises an AttributeError"""
+    x = 5
+    y = x.strip()
+
+# have to comment this out, because the SyntaxError keeps the code from
+# running at all
+# def syntax_error():
+#     """This function raises a SyntaxError"""
+#     del = 32  # this one is tricky -- it's an error because "del" is a keyword
+
+# now run the functions:
+# Note: I have all but one commented out, becaue the code stops running
+#       when the first Error is hit.
+
+# name_error()
+# type_error()
+attribute_error()

solutions/Lesson01/codingbat/Logic-1/cigar_party.py

@@ -0,0 +1,45 @@
+#!/usr/bin/env python
+
+
+def cigar_party(cigars, is_weekend):
+    """
+    basic solution
+    """
+    if is_weekend and cigars >= 40:
+            return True
+    elif 40 <= cigars <= 60:
+        return True
+    return False
+
+
+def cigar_party2(cigars, is_weekend):
+    """
+    some direct return of bool result
+    """
+    if is_weekend:
+        return (cigars >= 40)
+    return (cigars >= 40 and cigars <= 60)
+
+
+def cigar_party3(cigars, is_weekend):
+    """
+    conditional expression
+    """
+    return (cigars >= 40) if is_weekend else (cigars >= 40 and cigars <= 60)
+
+if __name__ == "__main__":
+    # some tests
+
+    assert cigar_party(30, False) is False
+    assert cigar_party(50, False) is True
+    assert cigar_party(70, True) is True
+    assert cigar_party(30, True) is False
+    assert cigar_party(50, True) is True
+    assert cigar_party(60, False) is True
+    assert cigar_party(61, False) is False
+    assert cigar_party(40, False) is True
+    assert cigar_party(39, False) is False
+    assert cigar_party(40, True) is True
+    assert cigar_party(39, True) is False
+
+    print("All tests passed")

solutions/Lesson01/codingbat/README.rst

@@ -0,0 +1,7 @@
+CodingBat Solutions
+====================
+
+A few selected solutions from the codingbat site:
+
+http://codingbat.com/python
+

solutions/Lesson01/codingbat/Warmup-1/diff21.py

@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+
+
+def diff21(n):
+    """
+    basic solution
+    """
+    if n > 21:
+        return 2 * (n - 21)
+    else:
+        return 21 - n
+
+
+def diff21b(n):
+    """
+    direct return of conditional expression
+    """
+    return 2 * (n - 21) if n > 21 else 21 - n
+
+if __name__ == "__main__":
+    # needs
+    print(diff21(3))
+    print(diff21b(3))

solutions/Lesson01/codingbat/Warmup-1/monkey_trouble.py

@@ -0,0 +1,56 @@
+#!/usr/bin/env python
+
+#############################
+# Warmup-1 > monkey_trouble
+
+
+def monkey_trouble(a_smile, b_smile):
+    """
+    really simple solution
+    """
+    if a_smile and b_smile:
+        return True
+    elif not a_smile and not b_smile:
+        return True
+    else:
+        return False
+
+
+def monkey_trouble2(a_smile, b_smile):
+    """
+    slightly more sophisticated
+    """
+    if a_smile and b_smile or not (a_smile or b_smile):
+        return True
+    else:
+        return False
+
+
+def monkey_trouble3(a_smile, b_smile):
+    """
+    conditional expression -- kind of ugly in this case
+    """
+    result = True if (a_smile and b_smile or not (a_smile or b_smile)) else False
+    return result
+
+
+def monkey_trouble4(a_smile, b_smile):
+    """
+    direct return of boolean result
+    """
+    return a_smile and b_smile or not (a_smile or b_smile)
+
+if __name__ == "__main__":
+    # a few tests
+
+    # neat trick to test all versions:
+    for test_fun in (monkey_trouble,
+                     monkey_trouble2,
+                     monkey_trouble3,
+                     monkey_trouble4):
+        assert test_fun(True, True) is True
+        assert test_fun(False, False) is True
+        assert test_fun(True, False) is False
+        assert test_fun(False, True) is False
+
+    print("All tests passed")

solutions/Lesson01/codingbat/Warmup-1/not_string.py

@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+
+
+def not_string(st):
+    if st.startswith('not'):
+        return st
+    else:
+        return 'not ' + st
+

solutions/Lesson01/codingbat/Warmup-1/pos_neg.py

@@ -0,0 +1,27 @@
+#!/usr/bin/env python
+
+
+def pos_neg(a, b, negative):
+    if negative:
+        return a < 0 and b < 0
+    else:
+        return (a < 0 and b > 0) or (a > 0 and b < 0)
+
+if __name__ == "__main__":
+    # run some tests if run as script
+    # (from the codingbat site -- not all, I got bored)
+    assert pos_neg(1, -1, False) is True
+    assert pos_neg(-1, 1, False) is True
+    assert pos_neg(-4, -5, True) is True
+    assert pos_neg(-4, -5, False) is False
+    assert pos_neg(-4, -5, True) is True
+
+    assert pos_neg(-6, -6, False) is False
+    assert pos_neg(-2, -1, False) is False
+    assert pos_neg(1, 2, False) is False
+    assert pos_neg(-5, 6, True) is False
+    assert pos_neg(-5, -5, True) is True
+
+
+
+    print "all tests passed"

solutions/Lesson01/codingbat/Warmup-1/sleep_in.py

@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+
+
+def sleep_in(weekday, vacation):
+    """
+    basic solution
+    """
+    if (not weekday) or vacation:
+        return True
+    else:
+        return False
+
+
+def sleep_in2(weekday, vacation):
+    """
+    direct return of boolean result
+    """
+    return (not weekday) or vacation

solutions/Lesson02/fizz_buzz.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+
+"""
+Fizz Buzz examples -- from most straightforward, to most compact.
+"""
+
+
+# basic approach:
+def fizzbuzz1(n):
+    for i in range(1, n + 1):
+        if i % 3 == 0 and i % 5 == 0:
+            print("FizzBuzz")
+        elif i % 3 == 0:
+            print("Fizz")
+        elif i % 5 == 0:
+            print("Buzz")
+        else:
+            print(i)
+
+
+def fizzbuzz2(n):
+    """
+    Why evaluate i%3 and i%5 twice?
+    """
+    for i in range(1, n + 1):
+        msg = ''
+        if i % 3 == 0:
+            msg += "Fizz"
+        if i % 5 == 0:
+            msg += "Buzz"
+        if msg:
+            print(msg)
+        else:
+            print(i)
+
+
+def fizzbuzz3(n):
+    """
+    Or print on one line...
+    """
+    for i in range(1, n + 1):
+        if i % 3 == 0:
+            print("Fizz", end="")
+        if i % 5 == 0:
+            print("Buzz", end="")
+        elif i % 3: # have to somehow check if you need to print the number
+            print(i, end="")
+        print()
+
+
+def fizzbuzz4(n):
+    """
+    use conditional expressions:
+    """
+    for i in range(1, n + 1):
+        msg = "Fizz" if i % 3 == 0 else ''
+        msg += "Buzz" if i % 5 == 0 else ''
+        print(msg or i)
+
+
+def fizzbuzz5(n):
+    """
+    a one liner
+    """
+    for i in range(1, n + 1): print (("Fizz" * (not (i % 3)) + "Buzz" * (not (i % 5))) or i)
+
+
+if __name__ == "__main__":
+    fizzbuzz1(16)
+    print()
+    fizzbuzz2(16)
+    print()
+    fizzbuzz3(16)
+    print()
+    fizzbuzz4(16)
+    print()
+    fizzbuzz4(16)
+    print()

solutions/Lesson02/fizz_buzz_one_liner.py

@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+
+# This One Liner solution to the Fizz Buzz problem
+# was found by a student on the internet
+
+for i in range(1,101): print([i,'Fizz','Buzz','FizzBuzz'][(i%3==0)+2*(i%5==0)])
+
+# this is a good example of why the most compact code is not always the
+# best -- readability counts!
+# And this is pretty impenatrable.
+# but it's also pretty nifty logic, so below,
+# It's unpacked to make it easeir to understand.
+
+# first, add some white space to make it pep8 compatible, and more readable.
+
+for i in range(1, 101): print([i, 'Fizz', 'Buzz', 'FizzBuzz'][(i % 3 == 0) + 2 * (i % 5 == 0)])
+
+# second, take the for loop off one line -- that really makes no difference:
+
+for i in range(1, 101):
+    print([i, 'Fizz', 'Buzz', 'FizzBuzz'][(i % 3 == 0) + 2 * (i % 5 == 0)])
+
+# so we are looping through the numbers, and the contents of the print()
+# is deciding what to print for i
+
+# unpack that line:
+
+for i in range(1, 101):
+    options_to_print = [i, 'Fizz', 'Buzz', 'FizzBuzz']
+    index = 0  # default index is zero
+    index += (i % 3 == 0)  # add one to index if it's a multiple of 3
+    index += (2 * (i % 5 == 0))  # add two to the index if a multiple of 5
+    print(options_to_print[index])  # print the selection.
+
+# there are 4 possible options that might get printed on each line:
+# 1) the number, i
+# 2) Fizz
+# 3) Buzz
+# 4) FizzBuzz
+
+# we now need an index to pick which of these to print
+#
+# remember that True and False are also the integers 1 and 0:
+# so (i % 3 == 0) will return 1 (True) if i is a multiple of 3
+# and 0 (False) if not
+# and (i % 5 == 0) will do the same for 5
+# so (2 * (i % 5 == 0)) will return either 0 or 2
+#
+# so if the number is a multiple of neither, index will be zero,
+# and we'll get the zeroth element of the list: i
+#
+# if i is a multiple of three (i % 3 == 0), then the index will be 1
+#
+# and if i is a multiple of 5 the index will then be 3 (1+2)
+# if it wasn't a multiple of three, then it will be 2 (0+2)
+#
+# so using the index will get the right element from the options list.
+#
+# pretty slick!