Oh yes, Python has an array type, but you must import module array:
# module array has Python's array type
import array
# Python25 use 'c' as the character typecode
# Python30 uses unicode character typecode 'u'
char_array = array.array('c', 'hello world')
print(char_array[0]) # h
print(char_array) # array('c', 'hello world')
# 'i' uses a signed integer of 2 bytes
int_array = array.array('i', [2, 4, -11])
print(int_array[2]) # -11
print(int_array) # array('i', [2, 4, -11])
# 'f' uses 4 bytes and 'd' uses 8 bytes per element
float_array = array.array('d', [1.0, 2.0, 3.14])
print(float_array[2]) # 3.14
for n in float_array:
print(n)
# get more information on module array
help('array')
Arrays are sequence types and behave very much like lists, except that the type of objects stored in them is constrained. The type is specified at object creation time. Arrays use up less space in memory, for a limited number of applications this is important.
scru commented: You knowledge of Python is astounding+5
In case you are looking for a project that you can apply your newly learned OOP concepts to, here is one suggestion:
Take a group of people and keep track of their personal information like first name, last name, gender, age, and let's say bowling score. You want to know who is the youngest bowler, who has the highest score, and is there an age-score relation.
Since just about everything in Python is an object, you are doing OOP already. Look at it this way, a class is just one more convenient tool to group things together. If the class concept bothers you, you can do major programming without it.
After all, there are older computer languages like C that have no OOP, yet huge programs like entire operating systems (unix), and the core of Python have been written with it.
As a general rule it is best to write these things the long way: if x == 4 and y == 4: or: if x == False and y == False: In case you don't remember the precendence rules, you can even use: if (x == False) and (y == False):
The str() function returns a normal string. Test it out:
s = u"a unicode string"
d = {}
d['a'] = s
print(d) # {'a': u'a unicode string'}
d['b'] = str(s) # str() converts s to a normal string
print(d) # {'a': u'a unicode string', 'b': 'a unicode string'}
Please do not mix tabs and spaces for indentations in your code. Makes a mess of your code when I copy it into my editor! Many editors have different spaces per tab settings. Use spaces only, preferably 4 spaces like most programmers use!
Your problem is here:
for j in array:
distance=mag(array[disk].pos-array[j].pos)
The array is a list of sphere objects, so each j is a sphere object. In array[j] you are trying to use j as a numeric index into the array. Maybe you could use j directly as j.pos
"If you feel a reluctant sneeze coming on, look at a bright light and it'll come" - one of the most ridiculous things I've ever heard, but is there any truth to it??
Vision is one of the most brain intensive task, and I can see how this would mask your will not to sneeze.
According to former Fed Chairman Alan Greenspan, the US housing bubble accounted for up to 70% of GDP growth in recent years. This bubble of high risk junk mortgages drove up housing prices and was nothing but virtual/fake value.
Obama openly talks and listens to the folks that actually suffer. Bush would have held his show in front of military folks at a some base. There is hope!
Build yourself a small library of uniform wxPython templates and give them filenames you can find. You will be surprised how much help they provide in cutting and pasting a wxPython program together. There are hints of these templates in the "Starting wxPython" thread. For instance: http://www.daniweb.com/forums/post626902-16.html
First of all, do yourself and the rest of us a big favor and do not use tabs for indentations. As you can see, your code shows up badly in the Daniweb code area. Most of us use 4 spaces for indentation.
Here is an example of wxPython's GridSizer to display BitmapButtons in a nice grid. The bitmap images in this case are provided by wxPython's ArtProvider:
# exploring wxPython's GridSizer, ArtProvider and BitmapButton
import wx
class MyFrame(wx.Frame):
def __init__(self, parent, mytitle, art_list):
wx.Frame.__init__(self, parent, wx.ID_ANY, mytitle,
size=(360, 255))
self.SetBackgroundColour('green')
self.art_list = art_list
# main sizer forms a border
vsizer = wx.BoxSizer(wx.VERTICAL)
# wx.GridSizer(rows, cols, vgap, hgap)
# art_list has 48 items so make it 6x8
gsizer = wx.GridSizer(6, 8, 5, 5)
self.btn = range(len(self.art_list))
# fill the drid sizer using a loop
for ix, art in enumerate(self.art_list):
# set up a consecutive unique id for each button
id = 1000 + ix
bmp = wx.ArtProvider.GetBitmap(art, wx.ART_OTHER, (16, 16))
self.btn[ix] = wx.BitmapButton(self, id, bitmap=bmp)
# the gridsizer fills left to right one row at a time
gsizer.Add(self.btn[ix], 0, wx.ALL|wx.EXPAND, border=2)
self.btn[ix].Bind(wx.EVT_BUTTON, self.btnClick)
# add to the main sizer and set
vsizer.Add(gsizer, 0, wx.EXPAND|wx.ALL, border=10)
self.SetSizer(vsizer)
def btnClick(self, event):
"""do something"""
# get the art_id of the button clicked from the art_list
art_id = self.art_list[event.GetId() - 1000]
# show the art_id in the frame title bar
self.SetTitle(str(art_id))
# constants of art items in ArtProvider
art_list = [
wx.ART_ADD_BOOKMARK,
wx.ART_DEL_BOOKMARK,
wx.ART_HELP_SIDE_PANEL,
wx.ART_HELP_SETTINGS,
wx.ART_HELP_BOOK,
wx.ART_HELP_FOLDER,
wx.ART_HELP_PAGE,
wx.ART_GO_BACK,
wx.ART_GO_FORWARD,
wx.ART_GO_UP,
wx.ART_GO_DOWN,
wx.ART_GO_TO_PARENT, …
There is also pixel graphics and vector graphics. In the more common pixel graphics an image is made up of pixels with a given location and colour. In vector graphics the image is calculated using a series of mathematical operations. The advantage of vector graphics is that is smoothly scalable. Mind you that this is all mildly simplified.
One major application of vector graphics is in the movie animation industry. Also many electronic games us it. You can build for instance a landscape from a bunch of calculated coloured triangles.
Put your hand on a hot stove for a minute, and it seems like an hour. Sit with a pretty girl for an hour, and it seems like a minute. THAT'S relativity.
raw_input gives gives a string, so for numbers you can do calculations with, you will have change the numeric string to a float: total_sales = float(raw_input('Please enter your total sales: '))
Something like this should be faster, since it avoids the use of function calls:
text = """\
A list of Pythonyms ...
pythonanism: spending way too much time programming Python
pythoncology: the science of debugging Python programs
pythondemic: something bad that lots of Pyton programmers do
pythonerous: something hard to do in Python
pythong: a short piece of Python code that works
pythonorean: someone who knows the esoteric technical aspects of Python
pythonus: something you don't want to do in Python
pythonym: one of these words
ptyhoon: someone who is really bad at Python
sython: to use someone else's Python code
pythug: someone who uses python to crash computers
Pythingy: a function or tool that works, but that you don't understand
Pythonian: somebody that insists on using a very early version of python
PythUH? - block of code that yields a very unexpected output
Pythealot: a Python fanatic
"""
spaces = 0
for c in text:
# add to the count of spaces
if c == " ":
spaces += 1
print( "This text has %d spaces" % spaces )
Man "I’d like to call you. What’s your number?" Woman "It’s in the phone book." Man "But I don’t know your name." Woman "That’s in the phone book too."
A dying man gathered three of his best friends, a Lawyer, a Doctor and a Clergyman at his bed side and handed each of them an brown envelope containing $50,000 in cash. He asked them to put these envelopes into his coffin before it gets closed and buried, so he could have some money in his after-life.
After the funeral the Clergyman is in tears and confesses to the others that he took $20,000 out of the envelope for a good church cause. The Doctor admits that he donated $30,000 of the envelope's content for medical research. The Lawyer is upset with his two old friends, "Why, I put a personal check of the full amount in the envelope!"
A typical application of what you want to achieve is this book page indexing program:
# create a page index using a word:pagenumber dictionary
def do_index(keyword, pagenumber, page_index):
"""
if keyword exists add pagenumber to that particular list
otherwise make new entry to index dictionary
"""
page_index.setdefault(keyword, []).append(pagenumber)
return page_index
page_index = {}
page_index = do_index('jump', 27, page_index)
page_index = do_index('girl', 45, page_index)
page_index = do_index('boy',99, page_index)
# appends 58 to pagenumber list at word 'jump'
page_index = do_index('jump', 58, page_index)
print(page_index)
print('-'*50)
# print pagenumber(s) for one keyword
print(page_index['jump'])
print('-'*50)
# remove a pagenumber
page_index['jump'].remove(27)
print(page_index['jump'])
"""
my result -->
{'jump': [27, 58], 'boy': [99], 'girl': [45]}
--------------------------------------------------
[27, 58]
--------------------------------------------------
[58]
"""
AVbin is a thin wrapper around FFmpeg a collection of audio and video codecs widely used in projects such as mplayer, xine, gstreamer and VLC. It is needed to play .ogg and .mp3 sound files download: avbin-win32-5.zip from http://code.google.com/p/avbin/ and install avbin.dll into Windows/System32 directory
AVbin and pyglet are also available for Unix/Linux systems.
Here is a typical pyglet example:
# load and show an animated gif file using module pyglet
# download module pyglet from: http://www.pyglet.org/download.html
# pyglet is available for Windows and Unix/Linux systems
# the animated dinosaur-07.gif file is in the public domain
# download from: http://www.gifanimations.com
# notice that the event loop uses a function decorator
import pyglet
# pick an animated gif file you have in the working directory
ag_file = "dinosaur-07.gif"
animation = pyglet.resource.animation(ag_file)
sprite = pyglet.sprite.Sprite(animation)
win = pyglet.window.Window(width=sprite.width, height=sprite.height)
# set window background color = (r, g, b, alpha)
# each value goes from 0.0 to 1.0
green = (0, 1, 0, 1)
pyglet.gl.glClearColor(*green)
@win.event
def on_draw():
win.clear()
sprite.draw()
pyglet.app.run()
Use SetBitmapSelected() only if you want the different image to show as long as the button is pressed. For what you have in mind, you may want to use SetBitmapLabel():
# playing with wxPython's
# wx.BitmapButton(parent, id, bitmap, pos, size, style)
# show a different image for selected (depressed) button
# change the button image on button click
import wx
class MyFrame(wx.Frame):
def __init__(self, parent, mytitle, mysize):
wx.Frame.__init__(self, parent, wx.ID_ANY, mytitle, size=mysize)
# create a BitmapButton as an input widget
# pick a button image file you have (.bmp .jpg .gif or .png)
image_file1 = r".\cards\Deck1.gif"
self.image1 = wx.Bitmap(image_file1)
image_file2 = r".\cards\DK.gif"
self.image2 = wx.Bitmap(image_file2)
self.button = wx.BitmapButton(self, wx.ID_ANY, bitmap=self.image1,
pos=(10, 20),
size=(self.image1.GetWidth()+15, self.image1.GetHeight()+15))
# bind mouse click event to an action
self.button.Bind(wx.EVT_BUTTON, self.on_click)
# create an output widget
self.label = wx.StaticText(self, wx.ID_ANY, "", pos=(10, 100))
def on_click(self, event):
"""response to button press/click"""
# changes the images on button click for 2.5 seconds
self.button.SetBitmapLabel(self.image2)
self.Update()
wx.Sleep(2.5)
self.button.SetBitmapLabel(self.image1)
app = wx.App()
# create a MyFrame instance and show the frame
MyFrame(None, 'testing the wx.BitmapButton()', (400, 300)).Show()
app.MainLoop()
I have used PyQT, it is okay, but the user base is tiny and there is precious little help and too few good examples out on the net. You post a question on PyQt and rarely ever get an answer.
It directs wxPython where to show errors/consoleIO. This will go to the console: app = wx.App(redirect = False) is the same as app = wx.App(False) or app = wx.App(0)
This will go to a special window: app = wx.App(True) or since this is the default app = wx.App()
When I develop a wxPython program with an IDE editor that has its own output windwow to show test prints and error messages, I use app = wx.App(0) Once everything works correctly, I simply remove the zero.
