# when you set up variables like ...
book = "Python for Nuts"
pages = 223
scripts = 77
 
# Python keeps this information in a local dictionary called up with vars()
print vars()  #  { ... , 'pages': 223, 'book': 'Python for Nuts', 'scripts': 77, ... }
 
# now you can show the results like this ...
print "%s has %s pages and contains a total of %s code examples" % (book, pages, scripts)
 
# or take advantage of vars() ...
print "%(book)s has %(pages)s pages and contains a total of %(scripts)s code examples" % vars()

# manage the contents of a basket
# note: 
#   "self" keeps track of instances, here basket1 and basket2
#   it has to be the first argument of a class method/function
 
class Basket(object):
    """
    a class to add elements to a list and display the result
    default is an empty basket
    """
    def __init__(self, contents=[]):
        # make a true copy of contents list to avoid surprises
        contents = contents[:]
        self.contents = contents
 
    def add(self, element):
        # add elements to the basket (list)
        self.contents.append(element)
 
    def remove(self, element):
        # remove an element from the basket
        if element in self.contents:
            self.contents.remove(element)
        else:
            print element, " not in basket!"
 
    def print_me(self):
        # print out the list elements as a string
        result = " ".join(self.contents)
        print "Basket now contains:", result
 
 
# basket1 instance of the class, it is an empty basket
basket1 = Basket()
# add items to basket1
basket1.add('pins')
basket1.add('needles')
basket1.add('wurst')
 
# basket2 instance starts out with contents of basket1
# and allows the user to add more elements
basket2 = Basket(basket1.contents)
 
basket1.print_me()
print "Add things to the basket, use -thing to remove it:"
while True:
    thing = raw_input("Enter a thing (press Enter only to exit): ")
    if thing:
        if thing[0] == '-':
            basket2.remove(thing[1:])
        else:
            basket2.add(thing)
        basket2.print_me()
    else:
        break
 
# final tally, show things now in basket2
print "Final tally:"
basket2.print_me()

# a Python linear equation solver
 
def solve(eq, var='x'):
    eq1 = eq.replace("=", "-(") + ")"
    #print eq1   # test
    c = eval(eq1, {var:1j})
    #print c     # test
    return -c.real/c.imag
 
 
eq = "x-2 = 2*x"  # example
r = solve(eq)
print "equation: %s\n  result: x = %s" % (eq, r)

# class Teacher and class Student inherit from class SchoolMember
 
# the base or super class
class SchoolMember(object):
    '''represents any school member'''
    def __init__(self, name, age):
        self.name = name
        self.age = age
 
    def detail(self):
        '''show name and age, stay on same line (trailing comma)'''
        print 'Name: %-13s Age:%s' % (self.name, self.age),
 
# use the base class as argument to inherit from
class Teacher(SchoolMember):
    '''represents a teacher'''
    def __init__(self, name, age, subject):
        # call the base class constructor ...
        # it assigns name, age to self.name, self.age
        SchoolMember.__init__(self, name, age)
        self.subject = subject
 
    def detail(self):
        '''teaches this course'''
        SchoolMember.detail(self)
        print 'Teaches course: %s' % self.subject
 
class Student(SchoolMember):
    '''represents a student'''
    def __init__(self, name, age, grades):
        SchoolMember.__init__(self, name, age)
        self.grades = grades
 
    def detail(self):
        '''student grades'''
        SchoolMember.detail(self)
        print 'Average grades: %d' % self.grades
 
# teacher has name age and subject taught
t1 = Teacher('Mr. Schard', 40, 'Beginning Python 101')
# student has name, age and average grade (max 100)
s1 = Student('Abigale Agat', 20, 92)
s2 = Student('Bertha Belch', 22, 65)
s3 = Student('Karl Kuss', 21, 98)
s4 = Student('Tom Tippit', 22, 77)
s5 = Student('Zoe Zeller', 20, 88)
 
print '-'*55
 
# list of instances, Teacher t1 and Students s1 ... s5
members = [t1, s1, s2, s3, s4, s5]
sumgrades = 0
for member in members:
    memberType = member.detail()
    try:
        sumgrades += member.grades
    except AttributeError:
        pass # this would be a teacher, has no grades so skip
 
print "\n%s's students class-average grades = %d" % (t1.name, sumgrades/5)
 
"""
output =
Name: Mr. Schard    Age:40 Teaches course: Beginning Python 101
Name: Abigale Agat  Age:20 Average grades: 92
Name: Bertha Belch  Age:22 Average grades: 65
Name: Karl Kuss     Age:21 Average grades: 98
Name: Tom Tippit    Age:22 Average grades: 77
Name: Zoe Zeller    Age:20 Average grades: 88
 
Mr. Schard's students class-average grades = 84
"""

# modules should be saved to the same folder as the 
# program or to folders listed in sys.path()
 
# save this module code as apple.py ...
# (module-name and file-name.py have to match, are case sensitive!)
 
def pieCookingStatus(cooking_time):
    if cooking_time < 35:
        print "Still cooking!"
    elif cooking_time < 40:
        print "Almost done!"
    else:
        print "Take pie out of the oven!"
 
def piePercentCooked(cooking_time):
    """consider 40 minutes the fully cooked time"""
    return 100 * cooking_time/40
 
# optional, specify version number of module
version = '1.2'
 
# this test runs when this code is used as a standalone program, 
# but not as an imported module of another program,
# then the namespace will be apple (name of module) and not __main__
if __name__ == '__main__':
    print "Pie is %d percent cooked." % piePercentCooked(33)
    pieCookingStatus(33)

# test the module apple.py
 
# import creates a namespace with the module's name (apple)
# also Python creates a precompiled bytecode file apple.pyc for speed
import apple
 
# optional, check version if it has been specified
if 'version' in dir(apple):
  print 'Version =', apple.version
 
# optional, show namespaces used
# note that namespace __name__ is assumed for this program
# you don't have to use it, but you have to prefix the 
# modules namespace to functions/variables of the module
# in this case prefix with apple and a dot
print "Namespace of program:", __name__        # __main__
print "Namespace of module :", apple.__name__  # apple
 
# also optional, list filenames used
print __file__         # C:/Python24/Atest/AppleTest.py
print apple.__file__   # C:/Python24/Atest/apple.pyc
 
# now let's do something with the apple module
minutes_cooking = 45
percent_cooked = apple.piePercentCooked(minutes_cooking)
print "Pie is %0.1f percent cooked." % percent_cooked
apple.pieCookingStatus(minutes_cooking)

"""
your program myprog.py may be in C:\Python24\myprog.py
the module is in C:\Python24\directory1\directory2\module1.py
C:\Python24\ would be listed in sys.path() (PYTHONPATH)
"""
 
# import modules from subfolders:
from directory1.directory2 import module1

# sort a list of names by last name
 
def sort_names(names):
    """
    sort names by last name, avoiding title, first and middle names
    """
    names_mod = []
    for name in names:
        # split each name into a list
        name_list = name.split()
        # pick the last name from list
        last_name = name_list[-1]
        # create a list of temporary sublists [last_name, name] 
        names_mod.append([last_name, name])
    # sort the modified list of names inplace
    # this will sort by the first item in the 
    # sublists which is last_name
    names_mod.sort()
    # use list comprehension to
    # to remove the temporary last_name item
    return [name[1] for name in names_mod]
 
names = [
"Dr. Heidi Karin Hirsch",
"Miss Arlene Auerbach",
"Mr. and Mrs. Larry Zoom",
"Mr. Frank Paul Lummer",
"Vicepresident Colter"
]
 
print "Original list of names:"
for name in names:
    print name
 
print
print "List of names sorted by last name:"
names_sorted = sort_names(names)
for name in names_sorted:
    print name
 
"""
output -->
Original list of names:
Dr. Heidi Karin Hirsch
Miss Arlene Auerbach
Mr. and Mrs. Larry Zoom
Mr. Frank Paul Lummer
Vicepresident Colter
 
List of names sorted by last name:
Miss Arlene Auerbach
Vicepresident Colter
Dr. Heidi Karin Hirsch
Mr. Frank Paul Lummer
Mr. and Mrs. Larry Zoom
"""