python copy string from position to position
Understanding slice notation
How can I get a DisplayLink USB monitor work under Ubuntu? I have a DisplayLink-based external USB monitor, which has both power and data over USB, and seems to work perfectly under Windows 7, but only can display a text console under Ubuntu 10.10, and that I can only use when I am actually switched to it. So the only Use I can have so far is to have some text-based monitoring or console that I can watch while working on the graphic display.   I know there are some development done for DisplayLink, but I never could get it to actually run properly.   Yes, I tried the detailed setup described in other , but they did not work, and instead crashed my X that I had to restore.   Merci :-) I'm trying to set an alias for sudo !! in Bash. I tried alias sbb='sudo !!', but it interprets that as a literal  !! and prints   sudo: !!: command not found   If I use double quotes, it substitutes the double bang in the string itself, so that doesn't work.  Is there any way to make this work? Or an alternative alias? ` Some questions on abelian category Let  $f: C \longrightarrow D$ be a morphism in an abelian category $\mathfrak{A}$ with kernel and cokernel both zero. How can I show that it is an isomorphism? I am not able to find it's inverse.   Let $g: C \longrightarrow D$ be a morphism in the abelian category $\mathfrak{A}$. Let $i: K \hookrightarrow C$ be the kernel of $g$. How can I prove that the induced map $\text{coker}\ i \rightarrow D$ is a monic?   I don't want to use Mitchell's embedding theorem. Where can I find information about upcoming special issues in a field of study? How can I find information about upcoming special issues related to a special field of study? There are good websites for upcoming conferences but I could not find any place to search for special issues. How to use HttpWebRequest (.NET) asynchronously? How can I use HttpWebRequest (.NET, C#) asynchronously? GUI for watching logs (tail and grep) Could you recommend a GUI application with powerful log watching capabilities?  Generally it would work as tail -f in GUI, but on top of that following features would be very useful:   filtering out some lines based on (regular) expressions  coloring some lines based on (regular) expressions interactive search saveable configuration easily applicable to different files notifications based on (regular) expressions   A similar tool on Windows is  and its paid version - Node Package Manager got corrupted in some way, now it cannot be installed Pivot rows into multiple columns Fully charged MacBook Air turns off when power cord removed I have a MacBook Air, 2009, with a recently replaced Apple battery in December 2012. Recently, when power cord comes off, the computer shuts down. Also, it usually will not restart unless power cord is attached. "Who to follow" or "whom to follow"? has a "who to follow" button on the upper side of the screen. Shouldn't it be "whom to follow"?   suggests that whom is the correct usage in a case like this. Horizontal scroll bar occludes text I've been running into this lately.  The scroll-bar gets stuck and makes it difficult to read the text.  I'm running Chrome Version 56.0.2924.87 (64-bit) on macos. Is the neutral wire considered safe? Distributional Laplacian of logarithm and the Dirac delta distribution Consider $S(\mathbb{R}^2)$ .  Consider $F(x) = \displaystyle\frac{1}{2 \pi} \ln|x| , x \in \mathbb{R}^2 - \{ 0 \}$.  I want to prove this  : $\Delta F = \delta $ in $S^{'}(\mathbb{R}^2).$  My try: For every $\varphi \in S({\mathbb{R}}^2)$ we have  $$\langle \Delta F, \varphi\rangle  = \langle F , \Delta \varphi\rangle  = \displaystyle\int_{\mathbb{R}^2} F(x) \Delta\varphi(x) \ dx = \displaystyle\lim_{r \rightarrow + \infty} \displaystyle\lim_{\epsilon \rightarrow 0^{+} } \displaystyle\int_{\epsilon \leq |x| \leq R} F(x) \Delta \varphi(x) \ dx $$  I don't know how to prove this :$\displaystyle\lim_{r \rightarrow + \infty} \displaystyle\lim_{\epsilon \rightarrow 0^{+} } \displaystyle\int_{\epsilon \leq |x| \leq R} F(x) \Delta\varphi(x) \ dx = \varphi (0) = \delta(\varphi)$  I don't know what to do from here. Kate forces itself to be the default application for HTML How to hide users from the GDM login screen? I have recently added several new users, that I need for qmail. Now they appear in the box in the login screen and clutter it, and I have to scroll to find my user. How can I hide those users from the login box? Can I travel within the US with an expired visa? I am an international student and authorized to stay in US for 2 years on my I-20 form. My visa expired on June this year and I need to fly to some states outside Georgia to visit colleges. Can I fly within the US?  If I can, what kind of document will the airport check when I depart? Will they notice my expired visa and turn me in to Homeland Security? In other words, will I get into trouble? Should constructors comply with the Liskov Substitution Principle? Change installed AppleScript version This morning after the new Fallout Shelter update (1.2), I saw a mysterious stranger hiding in one of my rooms. When he is tapped  there is a sound cue and he disappears in a puff of black vapor.   Does anyone know what's going on here? Today I was informed by VFS that my tourist visa for UAE got approved. I'm travelling to UAE on 16th December 2014 and returning on 7th Jan 2015. But when I checked the "valid until" date on the visa it states 30 December 2014.    Does this date mean I should return before December 30th? Should I get it corrected from VFS?