node10.html

Pythone Library reference. it is ok and simple.

    <TD align=left>sorts list</TD></TR>
  <TR>
    <TD align=left><TT>list.index("value")</TT></TD>
    <TD align=left>returns the index of the first place that <TT>"value"</TT> 
      occurs</TD></TR>
  <TR>
    <TD align=left><TT>list.append("value")</TT></TD>
    <TD align=left>adds an element <TT>"value"</TT> at the end of the 
  list</TD></TR></TBODY></TABLE>
<P>This next example uses these features in a more useful way: <PRE>menu_item = 0
list = []
while menu_item != 9:
        print "--------------------"
        print "1. Print the list"
        print "2. Add a name to the list"
        print "3. Remove a name from the list"
        print "4. Change an item in the list"
        print "9. Quit"
        menu_item = input("Pick an item from the menu: ")
        if menu_item == 1:
                current = 0
                if len(list) &gt; 0:
                        while current &lt; len(list):
                                print current,". ",list[current]
                                current = current + 1
                else:
                        print "List is empty"
        elif menu_item == 2:
                name = raw_input("Type in a name to add: ")
                list.append(name)
        elif menu_item == 3:
                del_name = raw_input("What name would you like to remove: ")
                if del_name in list:
                        item_number = list.index(del_name)
                        del list[item_number]
                        #The code above only removes the first occurance of
                        # the name.  The code below from Gerald removes all.
                        #while del_name in list:
                        #       item_number = list.index(del_name)
                        #       del list[item_number]
                else:
                        print del_name," was not found"
        elif menu_item == 4:
                old_name = raw_input("What name would you like to change: ")
                if old_name in list:
                        item_number = list.index(old_name)
                        new_name = raw_input("What is the new name: ")
                        list[item_number] = new_name
                else:
                        print old_name," was not found"
print "Goodbye"
</PRE>
<P>And here is part of the output: 
<P><PRE>--------------------
1. Print the list
2. Add a name to the list
3. Remove a name from the list
4. Change an item in the list
9. Quit

Pick an item from the menu: 2
Type in a name to add: Jack

Pick an item from the menu: 2
Type in a name to add: Jill

Pick an item from the menu: 1
0 .  Jack
1 .  Jill

Pick an item from the menu: 3
What name would you like to remove: Jack

Pick an item from the menu: 4
What name would you like to change: Jill
What is the new name: Jill Peters

Pick an item from the menu: 1
0 .  Jill Peters

Pick an item from the menu: 9
Goodbye
</PRE>
<P>That was a long program. Let's take a look at the source code. The line 
<TT>list = []</TT> makes the variable <TT>list</TT> a list with no items (or 
elements). The next important line is <CODE>while menu_item != 9:</CODE>. This 
line starts a loop that allows the menu system for this program. The next few 
lines display a menu and decide which part of the program to run. 
<P>The section: <PRE>current = 0
if len(list) &gt; 0:
        while current &lt; len(list):
                print current,". ",list[current]
                current = current + 1
else:
        print "List is empty"
</PRE>goes through the list and prints each name. <CODE>len(list_name)</CODE> 
tell how many items are in a list. If <TT>len</TT> returns <CODE>0</CODE> then 
the list is empty. 
<P>Then a few lines later the statement <TT>list.append(name)</TT> appears. It 
uses the <TT>append</TT> function to add a item to the end of the list. Jump 
down another two lines and notice this section of code: <PRE>item_number = list.index(del_name)
del list[item_number]
</PRE>Here the <TT>index</TT> function is used to find the index value that will 
be used later to remove the item. <CODE>del list[item_number]</CODE> is used to 
remove a element of the list. 
<P>The next section <PRE>old_name = raw_input("What name would you like to change: ")
if old_name in list:
        item_number = list.index(old_name)
        new_name = raw_input("What is the new name: ")
        list[item_number] = new_name
else:
        print old_name," was not found"
</PRE>uses <TT>index</TT> to find the <CODE>item_number</CODE> and then puts 
<CODE>new_name</CODE> where the <CODE>old_name</CODE> was. 
<P>
<H1><A name=SECTION001030000000000000000>Examples</A> </H1>
<P>test.py <PRE>## This program runs a test of knowledge

true = 1
false = 0

# First get the test questions
# Later this will be modified to use file io.
def get_questions():
    # notice how the data is stored as a list of lists
    return [["What color is the daytime sky on a clear day?","blue"],\
            ["What is the answer to life, the universe and everything?","42"],\
            ["What is a three letter word for mouse trap?","cat"]]
</PRE><PRE># This will test a single question
# it takes a single question in
# it returns true if the user typed the correct answer, otherwise false
def check_question(question_and_answer):
    #extract the question and the answer from the list
    question = question_and_answer[0]
    answer = question_and_answer[1]
    # give the question to the user
    given_answer = raw_input(question)
    # compare the user's answer to the testers answer
    if answer == given_answer:
        print "Correct"
        return true
    else:
        print "Incorrect, correct was:",answer
        return false
</PRE><PRE># This will run through all the questions
def run_test(questions):
    if len(questions) == 0:
        print "No questions were given."
        # the return exits the function
        return
    index = 0
    right = 0
    while index &lt; len(questions):
        #Check the question
        if check_question(questions[index]):
            right = right + 1
        #go to the next question
        index = index + 1
    #notice the order of the computation, first multiply, then divide
    print "You got ",right*100/len(questions),"% right out of",len(questions)

#now lets run the questions
run_test(get_questions())
</PRE>
<P>Sample Output: <PRE>What color is the daytime sky on a clear day?green
Incorrect, correct was: blue
What is the answer to life, the universe and everything?42
Correct
What is a three letter word for mouse trap?cat
Correct
You got  66 % right out of 3
</PRE>
<P>
<H1><A name=SECTION001040000000000000000>Exercises</A> </H1>
<P>Expand the test.py program so it has menu giving the option of taking the 
test, viewing the list of questions and answers, and an option to Quit. Also, 
add a new question to ask, "What noise does a truly advanced machine make?" with 
the answer of "ping". 
<P>
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<ADDRESS>Josh Cogliati <A 
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