so your sprites could look like this, in front of a transparent background (this is actually a icon, just for illustration) i thought about a minigame that you could play while a movie or whatever is playing in the background
Is it possible to get a fully transparent window in Pygame (see the desktop through it)?  I've found how to create a window without a frame, but there doesn't seem to be any obvious way to make it transparent.  I'd be willing to tie into system-specific technology/frameworks as long as there are solutions for both Windows and Mac OS X, but I'm not sure which direction to be looking.  The only topic I was able to find , which isn't something I can do for this particular project (needs to be Pygame).
Can someone explain me this  please I am a bit confused?  It's from a texbook I am reading (block cipher companion)  it says that:      each weak key has  $2^{32}$ fixed points $m$ where $\operatorname{DES}_w(m) = m$ ( $w$ is a DES weak key). In other words encrypting a fixed point gives exactly the same point. To see this consider the $2^{32}$ ciphertexts after 8 rounds of encryption for which the two 32 bit halves are equal. For a weak  DES key, the round keys of the eighth and ninth rounds are equal. Thus the intermediate texts after seven rounds and after nine rounds of encryption will be equal. Since the round keys of the 7th and the 10th rounds are equal, the intermediate texts after 6 rounds and after 10 rounds of encryption will be equal. Continuing like this it follows that the plaintext will be equal to the ciphertext.    Now did not quite get :   Why are there $2^{32}$ fixed points?  And why after the eighth round of encryption the two halves must be equal? What does the author mean by the intermediate texts exactly? And how are they being equal?   P.S.: This question is not asking for what the weak keys are. I am asking for "fixed points" not exactly weak keys. For this reason I think it is not a duplicate of any other question. There is one similar question to what I've asked for which I have checked and saw that no satisfactory answer has been given there either.  Here is the similar question with no proper answers: Auto confirm when running bash scripts? How can I install a package without installing some dependencies? I'm trying to install the package LaTeXila, and the output looks like this:  $ sudo apt-get install latexila --no-install-recommends Reading package lists... Done Building dependency tree        Reading state information... Done The following extra packages will be installed:   latexila-data latexmk luatex tex-common texlive-base texlive-binaries   texlive-common texlive-doc-base texlive-latex-base Suggested packages:   rubber texlive-latex-extra debhelper Recommended packages:   texlive texlive-latex-recommended texlive-luatex lmodern   texlive-latex-base-doc The following NEW packages will be installed:   latexila latexila-data latexmk luatex tex-common texlive-base   texlive-binaries texlive-common texlive-doc-base texlive-latex-base 0 upgraded, 10 newly installed, 0 to remove and 0 not upgraded. Need to get 29.3 MB of archives. After this operation, 74.5 MB of additional disk space will be used. Do you want to continue [Y/n]?   I don't want to install the texlive packages. I've installed texlive manually from . Any suggestions? I have $k$ pairs of samples from different distributions. For each pair of samples I want to check if the samples are taken from a normal distribution with the same mean and variance. I assume the normal distributions for each pair is different and independent of other pairs. I do not know the mean and variance of any of the distributions.  I am doing a two sample t-test for each of the pairs. I want to combine the $k$ resulting p-values.   I could use Fisher's method but I am wondering about the distribution of the average t-value. If these were z-values rather than t-values I would use Stouffer's z-test. I could also approximate the t-distribution with a z-distribution and than use Stouffer's z-test, but I am not sure if that is a good approximation.  Is there a test like Stouffer's z-test for t-values?  Is there a better way to combine the t-values? Read from location on console C# Prove the following inequality:   $$\dfrac{e^x + e^{-x}}2 \le e^{\frac{x^2}{2}}$$   This should be solved using Taylor series.  I tried expanding the left to the 5th degree and the right site to the 3rd degree, but it didn't help.  Any tips? Bluetooth indicator disappears on turning off bluetooth Everytime I turn off my bluetooth, the indicator icon in the system tray disappears, as opposed to just greying out as expected. Next time I need to go to the settings select bluetooth to turn it on, which makes the indicator to reappear.  Is there anyway I can make the indicator icon not disappear but stay greyed out when not in use? What can I do if my USB flash drive is write-protected or read-only? When I plug in my USB flash drive, it shows up on my computer as write-protected or read-only. I am unable to transfer data to it, nor can I modify or delete any files already stored on it. I also cannot repartition or reformat the drive using Windows Disk Management, DiskPart, GParted, or other tools. The drive does not have a write-protect switch.  Why did this happen and what can I do about it? Is there a way to remove the write protection?  (Note that this can happen with some memory cards, too, as they often use controllers similar to those used in flash drives. In some cases, the system may report that the drive or card was formatted successfully even though it was never actually formatted; the original data reappears when the device is reinserted.)     This question comes up often and the answers are usually the same. This post is meant to provide a definitive, canonical answer for this problem. Feel free to edit the answer to add additional details. Execution of a command locally after ssh tunneling I have a script file ./run_app.sh which contains of the following:  ssh -L 8888:localhost:8888 ubuntu@address ./run_website.sh   # it should be executed locally   but it tries to run the second line on the remote machine. Actually, I want to run it on my pc. Any idea? If in Pete's World there's no Doctor, how is there a Torchwood? Running programs in the background from terminal How do I run a program in the background of a shell, with the ability to close the shell while leaving the program running? Lets say my UI is having problems or for some reason, I need to boot up a program from the terminal window, say, nm-applet:  nm-applet   When it's started, it occupies the foreground of the terminal window.  Is there any simple way to run the program in the background without needing to leave the terminal open or have it occupy the whole terminal?  On that note, I did find a way to run programs from the terminal and have it allow for other inputs, by appending an ampersand (&amp;) to the command as such:  nm-applet &amp;   But this isn't much use as any processes started in the terminal are killed once the terminal is closed. Overview of basic facts about Cauchy functional equation The  asks about functions $f \colon \mathbb R \to \mathbb R$ such that $$f(x+y)=f(x)+f(y).$$ It is a very well-known functional equation, which appears in various areas of mathematics ranging from exercises in freshman classes to constructing useful counterexamples for some advanced questions. Solutions of this equation are often called . Also a few other equations related to this equation are often studied. (Equations which can be easily transformed to Cauchy functional equation or can be solved by using similar methods.) Is there some overview of basic facts about Cauchy equation and related functional equations - preferably available online? Let $$ f(x) =    \begin{cases}\begin{align}     1\quad&amp;\text{ if }\; 0\leq x \leq 1 \\     2 \quad&amp;\text{ if }\; 1&lt;x \leq 2 \\   \end{align}\end{cases}$$  Then $\int^2_0 f(x)dx=3$ and an anti derivative of f(x) is $$F(x)=\begin{cases}\begin{align}     x\quad&amp;\text{ if }\; 0\leq x \leq 1 \\     2x \quad&amp;\text{ if }\; 1&lt;x \leq 2 \\   \end{align}\end{cases}$$ But, $F(2)-F(0)=4-0=4 \neq 3.$ Why has this happened?  Find an anti-derivative $G(x)$ of $f(x)$ such that $G(2)-G(0)=3$, the correct answer.  My attempt: $F(2)-F(0)=4 \neq 3$ because we need to break it up into two parts like this: $\int^2_1 2x dx + \int^1_0 x dx = x^2|^2_0 + \frac{1}{2} x^2|^1_0 =4-1+\frac{1}{2}-0=3.5$ but this is not right either. :(  For the "Find an anti-derivative $G(x)$..."I'm completely lost but perhaps if we solve the first part then I'll understand what it's asking for there.  Any help would be appreciated. Validate that string contains only allowed characters in Ruby How do I save terminal output to a file? How do I save the output of a command to a file?  Is there a way without using any software? I would like to know how. What defines the maximum size for a command single argument? It started happening today... all of a sudden, no apparent reason!  Here's the output from df:   assp:~# df -k Filesystem           1K-blocks      Used Available Use% Mounted on /dev/simfs             6291456   1378384   4913072  22% / tmpfs                  8202680         0   8202680   0% /lib/init/rw tmpfs                  8202680         0   8202680   0% /dev/shm  assp:~# df -i Filesystem            Inodes   IUsed   IFree IUse% Mounted on /dev/simfs           55781934   83005 55698929    1% / tmpfs                2050670       2 2050668    1% /lib/init/rw tmpfs                2050670       1 2050669    1% /dev/shm  assp:~# df -h Filesystem            Size  Used Avail Use% Mounted on /dev/simfs            6.0G  1.4G  4.7G  22% / tmpfs                 7.9G     0  7.9G   0% /lib/init/rw tmpfs                 7.9G     0  7.9G   0% /dev/shm   Here's an actual entry from /var/log/mail.warn:   Dec 11 17:55:37 assp postfix/smtpd[30614]: warning: not enough free space in mail queue: 0 bytes &lt; 1.5*message size limit Dec 11 17:55:37 assp postfix/cleanup[30617]: warning: 4361D850D54: write queue file: No space left on device   . Why is my Nikon 50mm f/1.8 giving me an fEE error? I have a AF Nikkor 50mm f/1.8. When I have the aperture setting on the lens to 22 I can take photos. But when I change the dial to anything other than 22(lowest f/stop) then I get a flashing fEE message and r09 where the number of exposure left is.  I don't have the manual for this lens but am just wondering if anyone knows what the issue is here.  My camera is a Nikon D70S. How to open a folder in Finder by a single mouse click? (using Icon view) Is there a setting, key combination or similar to open a folder/subfolder in Finder with a single mouse click ?  I need a general solution which works on any folder in effort to minimize needless clicking ... that tiny triangle aside the folder icon will work yet its just too small and only appears using list view ... inspired by same behavior on osx inside a browser to hold down command key and single click a web link ... forcing users to double click is so 20th Century  Is there a way to enable this on macOS (High Sierra or higher)?  On ubuntu this single click preference is a simple setting ;-) I know the usage of     This is a new car.   This is singular.     These are some books for you.   These is plural.  Shall we use   There exists some people who agree with me. There exist some people who agree with me.   Which one is the correct usage and why?