When I shuffle several sublists they come out in the same order.  I'm sure I can reseed it with a random number each time, but everything I read implies that I shouldn't have to. Code:  test=[list(range(10))]*5 import random for x in test:     random.shuffle(x)  print(test)   Results:  [[0, 8, 9, 6, 1, 2, 7, 4, 5, 3], [0, 8, 9, 6, 1, 2, 7, 4, 5, 3], [0, 8, 9, 6, 1, 2, 7, 4, 5, 3], [0, 8, 9, 6, 1, 2, 7, 4, 5, 3], [0, 8, 9, 6, 1, 2, 7, 4, 5, 3]]   Why isn't shuffle producing different orders?
I needed to create a list of lists in Python, so I typed the following: my_list = [[1] * 4] * 3  The list looked like this: [[1, 1, 1, 1], [1, 1, 1, 1], [1, 1, 1, 1]]    Then I changed one of the innermost values: my_list[0][0] = 5  Now my list looks like this: [[5, 1, 1, 1], [5, 1, 1, 1], [5, 1, 1, 1]]    which is not what I wanted or expected. Can someone please explain what's going on, and how to get around it?
A sci-fi book or TV show about a tribesman discovering he or she actually lives in a huge spaceship The story starts with a tribesman going on a exploratory voyage around the land, meeting other progressively more and more distant tribes, learning about the world. Gradually he or she discovers that the "world" is actually a giant spaceship flying through space.  The story climaxes by the hero ascending to the commanding deck and learning who actually pilots the ship and to what purpose. Badge progress reports Is there a way to view your own progress towards certain badges? For example:   Tumbleweed - What value constitutes low views for a week? Fanatic  – Is there a way to view how many days in a row you currently have? Beta – Is it even possible to get this badge anymore? raw_input in python without pressing enter Why is my Canon 300D not switching on despite changing both batteries and the CF card? What are app domains used for? I have heard a few times that one way of describing quantum computers is that they essentially use the computing power of their counterparts in alternate realities that they access through superposition. My first question is, of course,    is this actually an accurate description of how quantum computers work, or just a misrepresentation?   Also, if it were to be assumed true and taken literally, then presumably all the possible outcomes of any given computation done would be experienced by each of these alternate realities. I have a few questions regarding the implications of this:   Would it be correct to say that our universe essentially "spawns" these alternate realities to use for each computation, or that they all exist simultaneously in a higher dimension and only come into contact via the initiation of superposition by each computer at the same time? Would it be possible to create contact between universes via this connection? I'd expect that, if it was, it would be entirely random, and so not only would not cause any information transfer, it also would be completely undetectable, because the deviations would be within the expected probabilities of error rates - but is there any way to circumvent this? Let $f$ be an entire function such that $\mid f(z) \mid \leq A \mid z \mid$ for all $z$, where $A$ is a fixed number. Show that $f(z)=a_1z$, where $a_1$ is a complex constant. Calculation of number density from material density Material density is given by $ \rho =m/V$, where $m$ is mass and $V$ is volume. Again number density given by $n=N/V$, where $N$ is the total number of particle. How can I calculate number density $n$ from material density $ \rho $. Show the reason given for a close vote before the question gets closed If a question gets votes to close but no answer or comment stating the reason for the vote, the OP has no way of knowing if editing would solve the problem.  Show to the asker the reasons (but not who voted) given for a vote to close so they can attempt to correct the problem without having to resort to begging for a reopen or reposting an edited version and risk being called a duplicate. Exports look fine but when printing on plotter, text disappears, using ArcMap I exported a map and everything looks fine when viewing the PDF. But when printing it on my plotter, all the text disappears. The scale bar would bring but the text associated to the scale bar wouldn't. The title block also disappears. I've tried messing around with the settings. I've checked/unchecked &quot;Embed All Document Fonts&quot; and &quot;Convert Marker Symbols to Polygons&quot;. I'm not sure what I'm doing wrong here. What's weird is I exported this map a few weeks ago and it printed just fine. Today, I needed to make a change to the map and exported it out, and now I am experiencing this issue. I must have changed one of the export settings in the past few weeks but I'm not sure what it is. Has anyone experienced this? Determine which app is drawing on top of other apps? Is there a way to determine which application is drawing on top of other applications?  For example, Facebook Messenger app can draw the chat bubbles on top of everything, but how do I know which app is doing this?  My problem:  I have an app which is drawing ads on top of everything and I wanna know which app is doing this. Not just to uninstall it, but to warn everyone that uses this app. (I didn't install any application recently and I already verified the recent updates.)  I tried to use the Dump View Hierarchy for UI Automator from the Android Studio, but it seems that the applications that draw on top can't be selected this way.  (Click image to enlarge) I've been reading a lot about dual-booting, and it seems as easy as loading Windows and then loading Linux with GRUB, but everybody says that Windows loves to trash GRUB when it gets the opportunity. What are some steps I can take to prevent this from happening (other than using Windows' bootloader, I want to keep this as simple as possible)? SQLite - UPSERT *not* INSERT or REPLACE Is there some clever way to do this in SQLite that I have not thought of? Basically I want to update three out of four columns if the record exists, If it does not exists I want to INSERT the record with the default (NUL) value for the fourth column. The ID is a primary key so there will only ever be one record to UPSERT. (I am trying to avoid the overhead of SELECT in order to determine if I need to UPDATE or INSERT obviously) Suggestions?  I cannot confirm that Syntax on the SQLite site for TABLE CREATE. I have not built a demo to test it, but it doesn't seem to be supported. If it was, I have three columns so it would actually look like: CREATE TABLE table1(      id INTEGER PRIMARY KEY ON CONFLICT REPLACE,      Blob1 BLOB ON CONFLICT REPLACE,      Blob2 BLOB ON CONFLICT REPLACE,      Blob3 BLOB  );  but the first two blobs will not cause a conflict, only the ID would So I assume Blob1 and Blob2 would not be replaced (as desired)  UPDATEs in SQLite when binding data are a complete transaction, meaning Each sent row to be updated requires:  Prepare/Bind/Step/Finalize statements unlike the INSERT which allows the use of the reset function The life of a statement object goes something like this:  Create the object using sqlite3_prepare_v2() Bind values to host parameters using sqlite3_bind_ interfaces. Run the SQL by calling sqlite3_step() Reset the statement using sqlite3_reset() then go back to step 2 and repeat. Destroy the statement object using sqlite3_finalize().  UPDATE I am guessing is slow compared to INSERT, but how does it compare to SELECT using the Primary key? Perhaps I should use the select to read the 4th column (Blob3) and then use REPLACE to write a new record blending the original 4th Column with the new data for the first 3 columns? "Dear Sir or Madam" versus "To whom it may concern" When is it appropriate to use the terms Dear Sir or Madam and To whom it may concern?  The rules I was taught state that Dear Sir or Madam should be used when you're writing a letter to a person about something that person has direct involvement in (e.g. returning a defective product to a customer service department).  By the same rules, To whom it may concern would be used for situations in which the recipient is a third party to the topic of the letter (e.g. regarding a letter of reference or recommendation).  Was I taught correctly?  Is the rule actually something else?  Or is this one of those situations where many people have an opinion but there is no real rule? Given the following HTML:   &lt;div id="container"&gt;   &lt;!-- Other elements here --&gt;   &lt;div id="copyright"&gt;     Copyright Foo web designs   &lt;/div&gt; &lt;/div&gt;    I would like #copyright to stick to the bottom of #container. Can I achieve this without using absolute positioning? Differences between hosting options for SharePoint apps What's the difference between  and ,  and ? What's the difference between &lt;b&gt; and &lt;strong&gt;, &lt;i&gt; and &lt;em&gt; in HTML/XHTML? When should you use each? Is there a nice solution to get a "presenter mode" for Latex presentations? I have two classes, Foo and Bar, that have constructors like this:  class Foo {     Foo()     {       // do some stuff     }      Foo(int arg)     {       // do some other stuff     } }  class Bar : Foo {     Bar() : base()     {       // some third thing     } }   Now I want to introduce a constructor for Bar that takes an int, but I want the stuff that happens in Bar() to run as well as the stuff from Foo(int).  Something like this:  Bar(int arg) : Bar(), base(arg) {   // some fourth thing }   Is there any way to do this in C#?  The best I have so far is putting the work done by Bar() into a function, that also gets called by Bar(int), but this is pretty inelegant. WinForms: How to programmatically fire an event handler? I want to programmatically invoke an event handler for a control. For example:  DateTimePicker dtpLastConsummated;   I want to trigger the TextChanged event handler for the dtpLastConsummated, how can i do it?  In other languages I would call something akin to:  dtpLastConsummated.TextChanged(this, new EventArgs());   but in .NET you can have multiple event handlers:  dtpLastConsummated.Click +=new EventHandler(dtpLastConsummated_TextChanged); dtpLastConsummated.Click +=new EventHandler(dtpLastConsummated_AnotherHandler); dtpLastConsummated.Click +=new EventHandler(dtpLastConsummated_MoreHandlers); ... dtpLastConsummated.Click +=new EventHandler(dtpLastConsummated_Nminus1);   so you need a way to trigger all the attached event handlers.    Answer  The following code will fire the event:  Toolkit.FireEvent(dtpLastConsummated, "TextChanged", new EventArgs());   And here's the code of the static toolkit function:  /// &lt;summary&gt; /// Programatically fire an event handler of an object /// &lt;/summary&gt; /// &lt;param name="targetObject"&gt;&lt;/param&gt; /// &lt;param name="eventName"&gt;&lt;/param&gt; /// &lt;param name="e"&gt;&lt;/param&gt; public static void FireEvent(Object targetObject, string eventName, EventArgs e) {    /*     * By convention event handlers are internally called by a protected     * method called OnEventName     * e.g.     *     public event TextChanged     * is triggered by     *     protected void OnTextChanged     *      * If the object didn't create an OnXxxx protected method,     * then you're screwed. But your alternative was over override     * the method and call it - so you'd be screwed the other way too.     */     //Event thrower method name //e.g. OnTextChanged    String methodName = "On" + eventName;     MethodInfo mi = targetObject.GetType().GetMethod(          methodName,           BindingFlags.Instance | BindingFlags.NonPublic);     if (mi == null)       throw new ArgumentException("Cannot find event thrower named "+methodName);     mi.Invoke(targetObject, new object[] { e }); }     Note: I'm not creating a subclass of every control in the .NET framework, and every 3rd party control, and convincing an enterprise worth of developers to retrofit every form to use my custom controls.