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--- public:t-vien-07-1:lab_1_materials [2007/01/16 15:08] – hannes
+++ public:t-vien-07-1:lab_1_materials [2024/04/29 13:33] (current) – external edit 127.0.0.1
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 ====== Lab 1 - Introduction to Python and Panda 3D ======
@@ Line 7: / Line 8: @@
   * NOTE: Both Python and Panda are available on Linux as well as Windows, you can pick!
   * NOTE: The Panda 3D distribution comes with Python 2.4, so you actually don't need to download and install Python separately!
-     * If you want it separte, install version 2.4.4 of [[http://www.python.org|Python]] (not version 2.5) on your machine  ([[http://www.ru.is/kennarar/hannes/share/python-2.4.4.msi|LOCAL PYTHON DOWNLOAD]])
+     * If you want it separate, install version 2.4.4 of [[http://www.python.org|Python]] (not version 2.5) on your machine  ([[http://www.ru.is/kennarar/hannes/share/python-2.4.4.msi|LOCAL PYTHON DOWNLOAD]])
   - Install the latest version of [[http://www.panda3d.org|Panda 3D]] on your machine ([[http://www.ru.is/kennarar/hannes/share/panda3d-1.3.0.exe|LOCAL PANDA DOWNLOAD]])
   - Install a Python code editor of choice:
-    * My favourite is [[http://www.ru.is/kennarar/hannes/share/SPE-0.8.3.c-wx2.6.1.0-py24.exe|Sani's Python Editor]], but you must first install the [[http://www.ru.is/kennarar/hannes/share/wxPython2.6-win32-unicode-2.6.3.3-py24.exe|wxPython GUI]] module
+    * My favorite is [[http://www.ru.is/kennarar/hannes/share/SPE-0.8.3.c-wx2.6.1.0-py24.exe|Sani's Python Editor]], but you must first install the [[http://www.ru.is/kennarar/hannes/share/wxPython2.6-win32-unicode-2.6.3.3-py24.exe|wxPython GUI]] module
     * You can also browse a [[http://wiki.python.org/moin/PythonEditors|list of other editors]]
 ===== Useful Links =====
@@ Line 27: / Line 29: @@
-==== Python ====
-  - Create a program called **''myhello.py''** that prints "Hello World!" on the screen. <code python>
+==== Introduction to Python ====
+To work through these exercises, use the reference material among the links above.  The hints are there for a quick reference, but you'll probably need to look a few things up as well.
+  - Create a program called **''myhello.py''** that prints "Hello World!" on the screen. \\ \\ <code python>
 # HINT: Typical print statement
 print "This gets printed!"
 </code>
-  - Add the function **''greet''** to your program, which takes a person's name as input and prints out a greeting addressed to that person.  Call your new function with your own name from within the program. <code python>
+  - Add the function **''greet''** to your program, which takes a person's name as input and prints out a greeting addressed to that person.  Call your new function with your own name from within the program.  \\ \\ <code python>
 # HINT: Declaring and calling a function
 def myfunc(x):
@@ Line 41: / Line 59: @@
 myfunc(3)
 </code>
-  - Declare a list of names, called **''friends''**, in your program and then make the program greet everyone on that list. <code python>
+  - Declare a list of names, called **''friends''**, in your program and then make the program greet everyone on that list.  \\ \\ <code python>
 # HINT: Printing out all the members of a list, regardless of type
 mylist = [1,3,5,'A','B']
@@ Line 47: / Line 65: @@
    print x
 </code>
-  - Instead of greeting each friend once, make the program greet one at random and repeat this process as many times as you specify on the command line when you launch it. <code python>
+  - Instead of greeting each friend once, make the program greet one at random and repeat this process as many times as you specify on the command line when you launch it.  \\ \\ <code python>
 # HINT: Picking a random entry
 import random # Import the 'random' functions module
@@ Line 70: / Line 88: @@
    print j
 </code>
-  - Add the class **''Item''** to your program.  Initialize the class properties **''name''**, **''material''** and ''**working**'' in the constructor, with the first two being passed in and the last one set to the default value of **''True''**.    Add the method **''use''**, which prints out "I can't use this broken [name]" if the item is not working, prints out "Dang! The [name] just broke!" if a test of material strength fails (see next) or prints out "The [name] really helped!" if nothing catastrophic occurs.  To help with testing the material strength, declare a global dictionary called ''**material_strength**'', keyed on material names (like **''"glass", "plastic", "wood", "metal"''**) and mapping them to strength values between 0 and 100.  The test for an item fails if a random value in the 0 to 100 range is higher than the strength of the item's named material.  Declare a global list of instanced items (like **''"hammer", "glasses", "blender", "raygun"''**...) and make the program use them all to see if your class works.<code python>
+  - Add the class **''Tool''** to your program.  This class represents a useful object that is made from some particular material.  The problem is that the tool sometimes breaks when it is being used, depending on its material strength.  You will simulate this behavior with this class.
+    - Initialize the **''Tool''** class properties **''name''**, **''material''** and ''**working**'' in the constructor, with the first two being passed in and the last one set to the default value of **''True''**.
+    - Add the method **''use''** to the class, which prints out "I can't use this broken [name]" if the tool is not working (''working is False''), prints out "Dang! The [name] just broke!" (ands sets ''working=False'') if a test of material strength fails (see next) or prints out "The [name] really helped!" if nothing catastrophic occurs.
+    - To help with testing the material strength, declare a global dictionary called ''**material_strength**'', keyed on material names (like **''"glass", "plastic", "wood", "metal"''**) and mapping them to strength values between 0 and 100 (your choice).
+    - The test in the **''use''** method of a tool fails if a random value in the 0 to 100 range is higher than the strength of the item's named material.
+    - Declare a global list of instanced tools (like **''"hammer", "glasses", "blender", "raygun"''**...) and make the program use them all to see if your class works. \\ \\ <code python>
 # HINT: Creating a new class
 class MyClass:
@@ Line 83: / Line 106: @@
    def show(self):
-      print "I have x="+self.x+" and y="+self.y
+      print "I have x="+str(self.x)+" and y="+str(self.y)
 # Let's creat an instance and call the show method
@@ Line 93: / Line 116: @@
 print mydict["B"] # Prints 30, which is the value associated with the key "B"
 </code>
-  - Make your list of friends now contain a list of touples where the first element is the friend's name like before, but the second element should be a list of 2-3 instanced items in that friend's posession.  Make your program pick one person at random, greet them, and then ask to borrow one random item from them and finally try to use that borrowed item.  As before, have the program repeat this as many times as you specify or until items have been unsuccessfully used 10 times in a row (you can make the ''**use**'' method return ''**True**'' or ''**False**'' to help you keep track).
+  - Make your list of friends now contain a list of tuples where the first element is the friend's name like before, but the second element should be a list of 2-3 instanced tools in that friend's possession.  Make your program pick one person at random, greet them, and then ask to borrow one random tool from them and finally try to use that borrowed tool.  As before, have the program repeat this as many times as you specify or until tools have been unsuccessfully used 10 times in a row (you can make the ''**use**'' method return ''**True**'' or ''**False**'' to help you keep track). \\ \\ <code python>
-  - Add the function **''fix''** to your program that takes in a single **''Item''** and forces its **''working''** value to **''True''**. Declare a list of names, called **''favorites''**, and instead of quitting after 10 failed attempts at using borrowed items, make the program fix all items posessed by those that have their name appear on the **''favorites''** list, but not the others.  Print out the names of those that got their items fixed and let the program borrow a few more items to see if it can now continue it's habit a bit longer.
+# HINT: A tuple is an immutable sequence, unlike a list which can be modified.
-  - Instead of using the **''favorites''**, only fix items for those that exist in the online Símaskrá (http://www.simaskra.is).
+mytuple = (3, 5, 7)
+# HINT: Tuples, like other sequences can contain any types of objects
+mytuple = (3, "Hello", MyClass(5), [7, 6, 4])
+# Any contained object can be referenced
+print mytuple[1]     # Prints "Hello"
+mytuple[2].show()    # Prints "I have x=5 and y=defaultY"
+print mytuple[3][0]  # Prints 7
+</code>
+  - Add the function **''fix''** to your program that takes in a single **''Tool''** and forces its **''working''** value to **''True''**. Declare a list of names, called **''favorites''**, and instead of quitting after 10 failed attempts at using borrowed tools, make the program fix all tools possessed by those that have their name appear on the **''favorites''** list, but not the others.  Print out the names of those that got their tools fixed and let the program borrow a few more tools to see if it can now continue it's habit a bit longer.  \\ \\ <code python>
+# HINT: Finding matches between two lists
+listA = [1, 3, 5, 7, 9]
+listB = [4, 5, 6, 8, 9]
+for x in listA:
+   if x in listB:
+      print str(x)+" is common!"  # Prints "5 is common!, 9 is common!"
+</code>
+  - Instead of using the **''favorites''**, only fix tools for those that exist in the online Símaskrá (http://www.simaskra.is).  \\ \\ <code python>
+# HINT: Reading and parsing a source on the Internet
+import urllib                # Module for simple Internet sockets
+from xml.dom import minidom  # Module for simple XML handling
+# We'll call the Yahoo RSS weather service and request info for Reykjavik (ICXX0002)
+rssweather_socket = urllib.urlopen("http://weather.yahoo.com/forecastrss?p=ICXX0002")
+rssweather_xml = minidom.parse(rssweather_socket)
+rssweather_socket.close()
+# We can extract XML elements by name (we get a list, but only take the first match)
+current_weather_element = rssweather_xml.getElementsByTagName("yweather:condition")[0]
+print "Current temperature is "+ current_weather_element.getAttribute("temp")+" deg."
+</code>