Merge branch 'master' of https://github.com/UWPCE-PythonCert/IntroPython-2017

Author: kmarguerite

materials/source/notes/session05.rst

@@ -67,7 +67,7 @@ similarly:
 
 ``for k in dict:``
 
-loops through the keys. So need for:
+loops through the keys. So no need for:
 
 ``for k in dict.keys():``
 

materials/source/notes/session06.rst

@@ -12,13 +12,61 @@ A collection of notes to go over in class, to keep things organized.
 Lightning Talks
 ===============
 
+Marlon M Estrada
+
+Ali Dehghani
+
 Alinafe Matenda
 
 Daniel W Kuchan
 
 Kathryn Egan
 
+Feedback
+========
+
+We got the results of the feedback survey last week.
+
+We really do read the comments and try to improve the class as we go.
+
+So Thanks!
+
+And you'll get another chance at the end of class, which we also appreciate.
+
 
 Issues that came up during the week.
 ====================================
 
+Getting an arbitrary key from a dict
+------------------------------------
+
+See ``arbitrary_key.py`` in `solutions/session04`
+
+dict as switch -- how do you leave the loop?
+--------------------------------------------
+
+Let's look at Eowyn's solution...
+
+
+globals??
+---------
+
+a number of you have been putting code in the global (module) namespace:
+
+.. code-block:: python
+
+   the_dict = {}
+
+   def fun():
+       ...
+       the_dict = something()
+
+What's wrong with this?
+
+More on keyword arguments:
+--------------------------
+
+:ref:`keyword_only_arguments`
+
+
+

solutions/Session04/mailroom2.py

@@ -30,7 +30,7 @@ def get_donor_db():
 
 def list_donors():
     """
-    creates a list of the donors as a string, so they can be printed
+    Create a list of the donors as a string, so they can be printed
 
     Not calling print from here makes it more flexible and easier to
     test
@@ -43,10 +43,9 @@ def list_donors():
 
 def find_donor(name):
     """
-    find a donor in the donor db
+    Find a donor in the donor db
 
     :param: the name of the donor
-
     :returns: The donor data structure -- None if not in the donor_db
     """
     key = name.strip().lower()
@@ -58,7 +57,6 @@ def add_donor(name):
     Add a new donor to the donor db
 
     :param: the name of the donor
-
     :returns: the new Donor data structure
     """
     name = name.strip()
@@ -88,7 +86,6 @@ def gen_letter(donor):
     Generate a thank you letter for the donor
 
     :param: donor tuple
-
     :returns: string with letter
 
     note: This doesn't actually write to a file -- that's a separate
@@ -104,22 +101,10 @@ def gen_letter(donor):
           '''.format(donor[0], donor[1][-1]))
 
 
-def send_thank_you():
+def take_donation(name):
     """
-    Execute the logic to record a donation and generate a thank you message.
+    Ask user for donation amount, and then add it  to the DB
     """
-    # Read a valid donor to send a thank you from, handling special commands to
-    # let the user navigate as defined.
-    while True:
-        name = input("Enter a donor's name (or list to see all donors or "
-                     "'menu' to exit)> ").strip()
-        if name == "list":
-            print(list_donors())
-        elif name == "menu":
-            return
-        else:
-            break
-
     # Now prompt the user for a donation amount to apply. Since this is
     # also an exit point to the main menu, we want to make sure this is
     # done before mutating the db.
@@ -149,9 +134,27 @@ def send_thank_you():
 
     # Record the donation
     donor[1].append(amount)
+    # print the thank you letter
     print(gen_letter(donor))
 
 
+def send_thank_you():
+    """
+    Execute the logic to record a donation and generate a thank you message.
+    """
+    # Read a valid donor to send a thank you from, handling special commands to
+    # let the user navigate as defined.
+    while True:
+        name = input("Enter a donor's name or 'list' to see all donors or "
+                     "'menu' to exit to main menu > ").strip()
+        if name == "list":
+            print(list_donors())
+        elif name == "menu":
+            return
+        else:
+            take_donation(name)
+
+
 def sort_key(item):
     # used to sort on name in donor_db
     return item[1]
@@ -192,6 +195,7 @@ def save_letters_to_disk():
         letter = gen_letter(donor)
         # I don't like spaces in filenames...
         filename = donor[0].replace(" ", "_") + ".txt"
+        print("writting letter to:", donor[0])
         open(filename, 'w').write(letter)
 
 
@@ -200,15 +204,19 @@ def print_donor_report():
 
 
 def quit():
+    """
+    quit the program
+
+    Note: you could put the sys.exit call directly in the dict
+          but this lets you put extra code in there if you want.
+    """
     sys.exit(0)
 
 
 if __name__ == "__main__":
 
     donor_db = get_donor_db()
 
-    running = True
-
     selection_dict = {"1": send_thank_you,
                       "2": print_donor_report,
                       "3": save_letters_to_disk,

solutions/Session05/dict_set_with_comps_solution.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+
+"""
+dict/set lab solutions: Chris' version.
+
+This time with comprehensions:
+"""
+
+food_prefs = {"name": "Chris",
+              "city": "Seattle",
+              "cake": "chocolate",
+              "fruit": "mango",
+              "salad": "greek",
+              "pasta": "lasagna"}
+
+# 1. Print the dict by passing it to a string format method, so that you
+# get something like:
+
+print("{name} is from Seattle, and he likes {cake} cake, {fruit} fruit,"
+      "{salad} salad, and {pasta} pasta".format(**food_prefs))
+
+# 2. Using a list comprehension, build a dictionary of numbers from zero
+# to fifteen and the hexadecimal equivalent (string is fine).
+
+print(dict([(i, hex(i)) for i in range(16)]))
+
+# 3. Do the previous entirely with a dict comprehension -- should be a one-liner
+
+print({i: hex(i) for i in range(16)})
+
+# 4. Using the dictionary from item 1: Make a dictionary using the same
+# keys but with the number of 'a's in each value. You can do this either
+# by editing the dict in place, or making a new one. If you edit in place,
+# make a copy first!
+
+print({key: val.count('a') for key, val in food_prefs.items()})
+
+
+# 5. Create sets s2, s3 and s4 that contain numbers from zero through twenty,
+# divisible 2, 3 and 4.
+
+#     a. Do this with one set comprehension for each set.
+s2 = {i for i in range(21) if not i % 2}
+s3 = {i for i in range(21) if not i % 3}
+s4 = {i for i in range(21) if not i % 4}
+
+
+print("\nHere are the three sets:")
+print(s2)
+print(s3)
+print(s4)
+
+#     b. What if you had a lot more than 3? -- Don't Repeat Yourself (DRY)
+#        - create a sequence that holds all three sets
+#        - loop through that sequence to build the sets up -- so no repeated code.
+
+n = 5
+divisors = range(2, n + 1)
+# create a list of empty sets
+sets = [set() for i in divisors]
+
+# fill up the sets
+for i, st in zip(divisors, sets):
+    [st.add(j) for j in range(21) if not j % i]
+
+print("\nHere are all the sets:\n", sets)
+
+
+# c. Extra credit:  do it all as a one-liner by nesting a set comprehension
+#    inside a list comprehension. (OK, that may be getting carried away!)
+
+sets = [{i for i in range(21) if not i % j} for j in range(2, n + 1)]
+
+print("\nHere are all the sets from the one liner:\n", sets)

solutions/Session05/except_exercise_solution.py

@@ -0,0 +1,54 @@
+#!/usr/bin/python
+
+"""
+An exercise in playing with Exceptions.
+Make lots of try/except blocks for fun and profit.
+Please remember to catch specifically the error you find,
+and not all errors.
+"""
+
+from except_test import fun, more_fun, last_fun
+
+
+# Figure out what the exception is, catch it and while still
+# in that catch block, try again with the second item in the list
+first_try = ['spam', 'cheese', 'mr death']
+
+try:
+    joke = fun(first_try[0])
+except NameError:
+    print("Whoops! there is no joke for: {}".format(first_try[0]))
+
+# Here is a try/except block. Add an else that prints not_joke
+try:
+    not_joke = fun(first_try[2])
+except SyntaxError:
+    print('Run Away!')
+else:
+    print(not_joke)
+
+# What did that do? You can think of else in this context, as well
+# as in loops as meaning: else if nothing went wrong.
+# (no breaks in  loops, no exceptions in try blocks)
+
+# Figure out what the exception is, catch it and in that same block
+# try calling the more_fun function with the 2nd language
+# in the list, again assigning it to next_joke.
+
+# If there are no exceptions, call the more_fun
+# function with the last language in the list
+# Regardless of whether there was an exception
+
+# Finally, while still in the try/except block
+# and regardless of whether there were any exceptions,
+# call the function last_fun with no parameters. (pun intended)
+
+langs = ['java', 'c', 'python']
+try:
+    more_joke = more_fun(langs[0])
+except IndexError:
+    more_joke = more_fun(langs[1])
+else:
+    more_joke = more_fun(langs[-1])
+finally:
+    last_fun()

solutions/Session05/except_test.py

@@ -0,0 +1,41 @@
+#!/usr/bin/env python3
+
+"""
+silly little test module that is designed to trigger Exceptions when
+run from the except_exercise.py file
+"""
+
+import time
+
+conclude = "And what leads you to that conclusion?"
+district = "Finest in the district, sir."
+cheese = "It's certainly uncontaminated by cheese."
+clean = "Well, it's so clean."
+shop = "Not much of a cheese shop really, is it?"
+cust = "Customer: "
+clerk = "Shopkeeper: "
+
+
+def fun(reaper):
+    if reaper == 'spam':
+        print(s)
+    elif reaper == 'cheese':
+        print()
+        print('Spam, Spam, Spam, Spam, Beautiful Spam')
+    elif reaper == 'mr death':
+        print()
+        return('{}{}\n{}{}'.format(cust, shop, clerk, district))
+
+
+def more_fun(language):
+    if language == 'java':
+        test = [1, 2, 3]
+        test[5] = language
+    elif language == 'c':
+        print('{}{}\n{}{}'.format(cust, conclude, clerk, clean))
+
+
+def last_fun():
+    print(cust, cheese)
+    time.sleep(1)
+    import antigravity

solutions/Session05/fizz_buzz_comprehension.py

@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+
+
+fb = [[str(i), 'Fizz', 'Buzz', 'FizzBuzz'][(i % 3 == 0) + 2 * (i % 5 == 0)] for i in range(1, 101)]
+
+print('\n'.join(fb))