I know that bytes.decode gives a string and string.encode gives the bytes, but only if the correct encoding is used.  Suppose I have a bytes object encoded using gb18030 If I try to decode it using big5:  &gt;&gt;name = '深入 damon' &gt;&gt;b1 = name.encode('gb18030') &gt;&gt;&gt; b1.decode('big5') UnicodeDecodeError: 'big5' codec can't decode byte 0xc8 in position 2: illegal multibyte sequence   Is there some way the encoding can be found from a bytes object? I couldn't find any useful api in this regard in python3docs.
I received some text that is encoded, but I don't know what charset was used. Is there a way to determine the encoding of a text file using Python?  deals with C#.
I'm tutoring high school students. I've always taught them that:     A charged particle moving without acceleration produces an electric as well as a magnetic field.   It produces an electric field because it's a charge particle. But when it is at rest, it doesn't produce a magnetic field. All of a sudden when it starts moving, it starts producing a magnetic field. Why? What happens to it when it starts moving? What makes it produce a magnetic field when it starts moving? Primary question: A common speaking mistake is to exchange syllables of words, saying "It's trace rhyme!" instead of saying "It's race time!", or pronouncing "kickin' chackatory" instead of "chicken cacciatore." Is there an existing name in poetry, linguistics, or English studies for switching syllables of (quasi-)consecutive words? I am not especially interested in the case when switching syllables results in interpretable homonyms or portmanteaus, like in the first example.  Secondary question: if not, what would you call it?  Tertiary question: is there somewhere a (playful?) taxonomy of fruitful or unfruitful lingual aberrations? How does friction stop a car? I'm unable to understand how friction causes motion in cars and also is responsible for stopping them. When it starts the impending motion of tyres is in the backward direction that's why friction is in the forward direction and the car starts moving. But when the car engine turns off, the car stops after some time, but the condition of tyres are the same as in the previous case and friction must be in the forward direction. newcommand vs. DeclareMathOperator As far as I understand, whatever can be done using DeclareMathOperator can also be achieved using newcommand, but not the other way around. If this is the case, what are the circumstances where DeclareMathOperator is the better choice? When should I take solely newcommand?  I found a question regarding , and I wonder what other aspects should be taken into consideration when it comes to choosing which method to use when defining math operators. What is the most convenient way to change options for Graph[] objects? Renting a car in Ireland & Great Britain: 1 rental or 2? My wife, two kids and I will be traveling in Ireland and the UK Nov. 1st through 21st. We're flying into and out of Dublin. Our plan is to do a clockwise tour: Fly into Dublin -> Belfast -> Scotland -> England/London -> Back to Dublin to fly home.  We've been planning to rent a car when we land in Dublin (doing just things outside Dublin at the start of the trip) and have a car all the way until London, then turn in the car and take a train/ferry to get back to Dublin before flying home.  However, reading through the car rental section of Rick Steve's 2012 Ireland book is causing us to question if this is the right plan.  He says (p. 480):     If your trip covers both Ireland and Great Britain, you're better off   with two separate car rentals, rather than paying for your car to ride   the ferry between the two islands. On an all-Ireland trip, you can   drive your rental car from the Republic of Ireland into Northern   Ireland, but be aware of drop-off charges ($75-150) if you return it   in the North.   So it seems like he recommends against doing one car rental for both islands, but he also recommends against renting in the Republic of Ireland and returning it in Northern Ireland (our other option for our current itinerary).  So we're not sure which is best here.  A few questions about this:   If we do one car rental all the way from Dublin to London, will there be a similar $75-$150 fee? Is there an easy place to return a car on the Northern Ireland side of one of the Northern Ireland -> Scotland ferries, and an easy place on the Scotland side to rent a car?  We'd like to minimize the number of buses/whatever we need to take between car rentals since we'll be lugging around car seats for both of our children (on top of carrying them and our luggage). Will one way be significantly cheaper than the other?  Besides the basic cost of taking the car on the ferry and the drop-off charges, our credit card will cover insurance in Scotland/England but not in Ireland, so we could potentially get a better rental rate by renting a second vehicle once we're on Great Britain. Although, I know you often get a better rate when keeping a car rental for longer, so that may negate any benefit from the credit card covering the insurance. How can you prove that a function has no closed form integral? Light "diode" and 2nd law of thermodynamics If I had a light "diode" - an object that only allowed light (at least for a range of frequencies) to travel through it in one direction, would this necessarily allow violations of the 2nd Law of Thermodynamics?  Or would it be possible to restrict other properties of the device such that it could be okay.  Why I think it should violate 2nd law:   I can place such devices at temperature T in a bath of thermal radiation at temperature T, such that it forms a box which only lets the light in or out.  This would appear to always allow one to create a thermal gradient.  Once a thermal gradient is formed, useful energy can be extracted.  This seems to allow useful energy to always be extracted from a thermal bath and thus give perpetual motion. Release one such device at temperature T in a bath of thermal radiation at temperature T.  Since the photons are absorbed or reflected in one direction, and undisturbed in the other, the device will start moving.  It can use a thermal bath to directly generate useful motion.   Why I think I'm missing something and such a device could potentially co-exist with the 2nd Law:   The above arguments seem valid if the diode was only 'partially' rectifying as well.  However there exist sunglasses which largely reflect on one side, but not from the other side. Researchers have succeeded in using meta-materials to create a "blackhole" for microwaves.   Can anyone help sort this out? What happens with the appearance of the folder icons in dark mode of macOS Mojave Finder? In High Sierra I used some custom icons for my folders in the Finder; but with the new update to Mojave and the dark mode, the predefined icons also become darker. However the custom icons don't.  Inspecting an element you find a dark preview, but when you extract the icon this is the clear, the same as there was in High Sierra. E.g.:   Previously visualization of the developer predefined icon. It's dark:  But if you extract that icon, it's clear:    There are no dark icons in the system library, at least not in the same directory as always:  /System/Library/CoreServices/CoreTypes.bundle/Contents/Resources   Are they being actively obscured by the operative system without there being icons with that real appearance? In this case, any idea to apply this method to the custom icons without modifying it into a new coloration? Prevent iMac from sleeping, for VPN login? We have an iMac in the office, and I have been getting inconsistent access when trying to log in to it. The firewall isn't going down, since I can connect to the VPN. After discussing it with the people at the office, we suspect that the iMac is going to sleep.   Is it possible to keep the iMac "awake" 24 hours a day? How do I instruct the people at the office to configure the iMac? What settings should be changed? The iMac is running OS X Lion 10.7.3. Expectation values of the position operator is equal to zero in case of even potentials? "At the time" versus "at that time" Sort ArrayList of custom Objects by property MapServer (MS4W) test page from shapefile shows only blank white square? I am trying to create a test page with mapserver and shapefile. At the moment I just want to get the map shown on my test page. I have gotten the EXTENT coordinates by opening shapefiles with QGIS - I am sure those are correct. I have followed this  as an example.  I am accessing my test page via this link:  http://localhost:1025/cgi-bin/mapserv.exe?map=C:\MS4W\ms4w\Apache\htdocs\mapfile.map   Problem I have - map is not loaded - I only see a blank white square.  When I look at contents of ms4w\Apache\htdocs\output , I see that images are actually getting generated but all of them are white (empty), for example:  lat_pmts_region13941906093724.png lat_pmts_region13941910095144.png lat_pmts_region13941913405500.png ...   Shapefiles are located at this location: C:\MS4W\ms4w\Apache\htdocs\shapefiles.  An example of what is logged to error file:  [Fri Apr 11 11:19:32 2014].883000 CGI Request 1 on process 7888 msWCSDispatch20(): wrong service (none) msWCSParseRequest(): request is KVP. msWCSDispatch(): SERVICE and REQUEST not included msDrawMap(): rendering using outputformat named png (AGG/PNG). msDrawMap(): WMS/WFS set-up and query, 0.000s msDrawMap(): Layer 0 (lat_pmts_region), 0.001s msDrawMap(): Drawing Label Cache, 0.000s msDrawMap() total time: 0.002s msSaveImage(C:/MS4W/ms4w/Apache/htdocs/output/lat_pmts_region13972043727888.png) total time: 0.138s [Fri Apr 11 11:19:33 2014].24000 mapserv request processing time (loadmap not incl.): 0.141s [Fri Apr 11 11:19:33 2014].24000 msFreeMap(): freeing map at 0246EFD8.   ms4w\Apache\htdocs\template.html:  &lt;html&gt; &lt;head&gt;&lt;title&gt;Mapserver Template HTML Document&lt;/title&gt;&lt;/head&gt; &lt;body bgcolor=#AAAAAA&gt; &lt;h2&gt;Template&lt;/h2&gt; &lt;img src="[img]" border=1&gt; &lt;/body&gt; &lt;/html&gt;   It looks like this:   C:\MS4W\ms4w\Apache\htdocs\mapfile.map:  MAP     CONFIG "MS_ERRORFILE" "C:/MS4W/ms4w/tmp/ms_error.txt"     DEBUG 5     NAME lat_pmts_region     STATUS ON     SIZE 800 600      EXTENT 286878.53 142087.25 799084.10 481123.75     #   lat_pmts_region      UNITS METERS     SHAPEPATH "shapefiles"     IMAGECOLOR 155 155 155      WEB     TEMPLATE "template.html"     IMAGEPATH "C:/MS4W/ms4w/Apache/htdocs/output/"     IMAGEURL "/output/"     END      LAYER     NAME "lat_pmts_region"     DATA lat_pmts_region     STATUS DEFAULT     TYPE POLYGON     END END   I will gladly provide more information if it's asked. Return vs. Enter? I noticed that my MacBook's keyboard has the word enter above the return key. I also noticed that on Mac OS X, there's a special symbol for return ↩, and another for enter ⌤. How would I send the enter key if my MacBook has no numpad?  Is there any difference between these two keys? How to remove \n from a list element? Change font of formula number in DisplayFormulaNumbered Ways to Install and uninstall programs in deb format I am embedding a PDF file inside my LaTeX-generated PDF file using embedfile:  \usepackage{embedfile} \embedfile{myfile.pdf}   I would like to also insert a link that the user can click on to open the attachment.  Is there any way to do that? Is there a better way than simply trying to open the file?  int exists(const char *fname) {     FILE *file;     if ((file = fopen(fname, "r")))     {         fclose(file);         return 1;     }     return 0; }