Interview Questions.

Question 1. How Do I Build Wxpython On Unix?

Answer :

This record describes how I build wxWidgets and wxPython at the same time as doing improvement and testing, and is supposed to help different people that need to do the same element. Those readers who have attempted this in preceding releases of the software will in all likelihood notice that this record is tons smaller than it became earlier than. Much thanks for this is going to Kevin Ollivier who wrote the initial model of the brand new construct scripts after which guilted me into starting to use and preserve them myself.

Building of each wxWidgets and wxPython is now treated via the wxPython/construct-wxpython.Py script within the source tree. It looks after all of the nasty and complicated information that was once documented in this file. Pretty an awful lot all you need to worry approximately now's having the construct equipment and dependent libraries mounted in your device and specifying wherein to install the consequences, if apart from the usual vicinity.

If you want to make modifications to any of the *.I documents, (SWIG interface definition documents,) then you may want to use a unique patched model of SWIG. Get the sources for version 1.3.29, after which follow the patches in wxPython/SWIG and then build SWIG like regular. See the README.Txt inside the wxPython/SWIG dir for details about each patch.

If you install this build of SWIG to a place that is not on the PATH (so it doesn't interfere with an current SWIG set up as an example) then you may set a SWIG environment variable to the full route of this new binary to tell the construct script which SWIG to use.

Question 2. How Do I Build Wxpython On Windows?

Answer :

The Windows builds presently require using Microsoft Visual C++. Theoretically, other compilers (inclusive of mingw32 or the Borland compilers) can also be used but I've in no way finished the paintings to make that occur. If you want to strive that then first you'll want to find out if there are any hints that have to be achieved to make Python extension modules the use of that compiler, after which make some modifications to setup.Py to house that. (And send the patches to me.) If you plan on using VisualStudio.Net (a.K.A. MSVC 7.1) understand that you may also must construct Python and any other extension modules that you use with that compiler because a different version of the C runtime library is used. The Python executable that comes from PythonLabs and the wxPython extensions that I distribute are constructed with MSVC 6 with all the Service Packs applied. This policy will change with Python 2.Four and MSVC 7.1 might be used beginning with that model.

If you need to build a debuggable version of wxWidgets and wxPython you will want to have also constructed a debug version of Python and every other extension modules you want to apply. You can tell if you have them already if there may be a _d inside the file names, as an instance python_d.Exe or python23_d.Dll. If you do not want to trace through the C/C++ parts of the code with the debugger then constructing the ordinary (or hybrid) version is first-class, and you can use the ordinary python executables with it.

Starting with 2.Five.Three.0 wxPython may be constructed for both the monlithic or the multi-lib wxWidgets builds. (Monolithic method that every one the middle wxWidgets code is in a single DLL, and multi-lib manner that the middle code is split into more than one DLLs.) To pick out which one to use specify the MONOLITHIC flag for each the wxWidgets build and the wxPython construct as shown underneath, putting it to either zero or 1. 

Just like the unix versions I additionally use a few scripts to help me construct wxWidgets, however I use some non-widespread stuff to do it. So when you have bash (cygwin or likely MSYS too) or 4NT plus unix-like cat and sed applications then there is a replica of my wxWidgets construct scripts in %WXDIRpercentwxPythondistribmsw. Just reproduction them to %WXDIRpercentbuildmsw and you can use them to do your construct, in any other case you may do the entirety with the aid of hand as described below. But in case you do work by way of hand and some thing doesn't appear to be running effectively please seek advice from the build scripts to see what may want to be achieved differently.

Perl Scripting Interview Questions
Question three. Python Crashes In Kernel32.Dll When I Import Wxpython In Windows 95?

Answer :

You can probably fix this via putting in winsock2

Question 4. I Don't Know C++, How Can I Use The Docs?

Answer :

Apart from the "wxPython Notes" and some articles below "Topic Overview" which you can locate useful, the maximum important components of the wxPython documentation, for the Python programmer, are:

The Alphabetical Class Reference
The list of Functions
This is the data which you may need to refer to over and over as you are developing your wxPython apps. Unfortunately, although, those references are written for C++ programmers, so genuinely all the method and characteristic definitions are in C++ layout, which makes it tough for a Python programmer to make experience of.

Perl Scripting Tutorial
Question five. I Ran "python Demo.Py" And All I Got Was This: Traceback (most Recent Call Last): File "demo.Py", Line three, In ? Import Main File "important.Py", Line 15, In ? From Wxpython.Wx Import * Importerror: No Module Named Wxpython.Wx When I Did A Search Of My Whole Python Directory, I Found No File Named Wxpython.Wx.

Answer :

In this context the dot way that it is looking for a module named wx positioned in a Python package named wxPython. Translated to the filesystem meaning a listing named wxPython with a record named wx.Py located within it. And an empty record named "init.Py" to make this folder a package deal.

This mistakes message approach that the wxPython listing isn't always located in a directory that is in the PYTHONPATH. To check your course run this from within Python:

import sys
print sys.Route

If the directory containing the wxPython directory isn't there you both want to transport wxPython or add the directory to PYTHONPATH. This may be performed either within the surroundings, in a sitecustomize.Py file (that is at the default direction) on within the registry on Win32. See the Python docs for extra details.

On Linux the wxPython RPM for Python 2 puts wxPython in /usr/neighborhood/lib/python2.0/web site-applications in view that Python 2 become installed in /usr/nearby on my construct machine. If Python 2 is in /usr to your machine then you may need to move (or link) wxPython to /usr/lib/python2.0/website online-programs.

On Win32 wxPython will install to the Python listing via default, which is automatically at the PYTHONPATH, so Python might be capable of find the modules the usage of the above syntax. If you set up elsewhere then you definately want to add that listing to the PYTHONPATH as defined above.

C++ Interview Questions
Question 6. Can I Use Wxpython Binaries With A Different Version Of Python?

Answer :

In wellknown, no. You need to use the equal version of Python as the wxPython binary was built with. That is why the version is a part of the filename.

Question 7. I've Looked At Tkinter And At Wxpython. Why Would I Choose One Or The Other?

Answer :

Installation: tkInter is a GUI toolkit that has been disbursed broadly with Python, and is effectively to be had to everyone who is jogging Python. WxPython requires a further install on pinnacle of the Python set up. If it's just for your personal machine, this isn't a large deal, however if you have a lot of individuals who want it, this could become a chunk of a huge deal.

Native Look and Feel: wxPython helps the native appearance and sense of the platform being used. TkInter has its very own appearance and experience for a few additives, which would not match any fashionable platform.

Windows XP and Python 2.2.2: In Python 2.2.2 beneath Windows XP you want this additional step:

Put  documents python.Exe.Appear and pythonw.Exe.Manifest, both with the subsequent contents:

 version="6.Zero.Zero.Zero" processorArchitecture="X86" publicKeyToken="6595b64144ccf1df" language="*" />

on your Python set up directory (wherein respective .Exe documents are living). Next time you run your wxPython applications, they will look like "normal" XP applications.

This may additionally have an effect on other Python modules that use Windows display API.

If you're the usage of py2exe to construct a standalone Python executable, say FOO.EXE, you want to copy pythonw.Exe.Happen into the directory where FOO.EXE is and call it FOO.EXE.Show up.

Wide Range of Available Widgets: wxPython has a much wider range of available widgets than does tkInter. There are additions to be had for tkInter that fairly mitigate this example, but this destroys the ease argument for tkInter. In addition, the wxPython toolkit has support for printing and other non-GUI, but also non-wellknown operations. TkInter is first-class if your utility is honestly a way of interacting with the person thru a GUI, however in case you need to increase a complete-scale software with support for drawing your very own UI factors, help for printing, and so forth., wxPython is really the manner to head.

C++ Tutorial PHP Interview Questions
Question 8. Is There A Mailing List For Help?

Answer :

Yes. You can join the listing, and examine the archives.

Question nine. How Do I Get Help From The Wxpython-customers Mailing List?

Answer :

When you have got a completely unique problem, it's time to ask a query on wxPython-users. Please comply with the fundamental policies of netiquet. Aside from them, there may be one component you could do to enhance your chances of getting a helpful answer if you have a few idea the way to do some thing, however it's now not quite operating:

Send a Complete, Working App that demonstrates your trouble or question. This app must be whole, in that it is able to be run, but as small as possible, in order that it isolates your hassle, and gives those of us that read the listing as little to take a look at as feasible.

This accomplishes  matters:

When keeping apart your problem, you may just find out why it wasn't running.
It makes it MUCH easier for us to help you, for some of motives:

We can simply run the app and see how it's behaving.
We can without difficulty tweak it, and attempt to find a solution.
Your trouble may not be in which you suspect it's miles. If you don't send a whole version, your trouble won't be in the code you ship, or be a feature of the way that code is used.
C Interview Questions
Question 10. What Is The Difference Between A Wxframe And A Wxwindow? When Do I Want To Use Each One?

Answer :

The terminology is a piece difficult. A wxFrame is what maximum folks think about as a Window: a box on the display screen that holds your application, and many others. It may be re-sized, moved, and so on with the mouse by using the window manager of the device.

A wxWindow is the primary unit from which all the controls, and so on. Are constructed. It is a rectangle on the display screen that captures mouse clicks, draws itself and many others. A wxWindow will almost constantly be placed into a Frame or different window.

You want to apply a body to create an unbiased box on the display screen to residence a few part of your application. You need to apply a wxWindow as the basis for a custom control of your very own design. All the integrated controls are derived from a wxWindow already.

PHP Tutorial
Question eleven. How Do I Use Multiple Threads?

Answer :

All calls to strategies of GUI items and occasion handlers want to manifest on the primary thread. In wxPython the main thread is the only that first imports the wxPython.Wx module. Other threads can ship activities to the principle thread the use of wxPostEvent as is completed within the Threads sample in the wxPython demo.

Ruby on Rails Interview Questions
Question 12. How Are Multiple Evt_xxx Calls Handled?

Answer :

I am questioning approximately how EVT_XXX handles multiple calls. I want to alternate
how events are dealt with relying upon which mode my application is in. If I name
EVT_XXX multiple times for the equal occasion, each time pointing to a specific
technique, are these event handlers chained or do subsequent calls update the
antique event handler?
Each example of a category derived from wxEvt

Handler has a static event table, that is used best by using C++ code, and a dynamic event desk (just a listing absolutely) that's what wxPython uses even though some C++ builders use it too. Every time you name a EVT_XXX function it provides an entry to this listing. When an occasion happens the primary matching handler in the event table is referred to as, and if it calls occasion.Skip() then the search maintains so if any other match is observed then it's far known as too. The EVT_XXX features are actually just convenience wrappers around the wxEvt

Handler.Connect method. There is likewise a .Disconnect approach that you could name if needed to get rid of an event handler binding.

Perl Scripting Interview Questions
Question thirteen. How Can I Use A Visual Debugger With Wxpython ?

Answer :

Most Debuggers (like IDLE or Python Win) use a exclusive GUI toolkit than wxPython does, and some debug the wxPython app inside their personal manner. This creates masses of conflicts between the wxPython occasion loop and the event loop of the debuggers' GUI tookit.

So, you want a debugger that debugs your program out-of-system. At present, HAP, Wing IDE and Komodo achieve this. HAP is open-source, so that you is probably interested in checking that one out;

C Tutorial
Question 14. How Do I Remove A Component, Or All Components Of A Certain Type From A Wxframe/wxpanel?

Answer :

If your container is the use of a sizer, you can get rid of all its children with this feature:

Toggle line numbers 

def removeChildren(self, ruin=1):
       """
Remove all my kids components and optionally
spoil them.
    """
whilst self.GetSizer().Remove(0):
 pass
if destroy:
self.DestroyChildren() 
To handiest remove kids of a particular kind (ie.WxStaticText), you can add a parameter to the approach, and do an isinstance() take a look at.

Question 15. How Do I Get A Wxgrid To Update Its Scrollbars?

Answer :

In wxPython 2.4.Zero.2, wxGrid seemingly does not update its scroll bars in response to changes within the rows and columns. You can cause it to try this by using callingFitInside() at the wxGrid object.

Ruby Interview Questions
Question sixteen. How Do I Hide The Row And Column Labels In A Wxgrid Window?

Answer :

Set the scale to zero. The label home windows will nonetheless exist, however they will now not be visible.

Grid.SetRowLabelSize(0)
grid.SetColLabelSize(zero)

(thanks PaulMcNett for the information)

Ruby on Rails Tutorial
Question 17. What's The Difference Between All The Dc Types?

Answer :

wxPaintDC can handiest be used inner a EVT_PAINT event and has greater information about what regions of the window were broken and need to be refreshed, allowing some optimization of the re-draw. You also can use this facts to optimize your redraw if you need.

WxClientDC may be used every time for drawing to the window, but you need to make certain that whatever you draw then is likewise redrawn in a EVT_PAINT event in any other case it will get lost the subsequent time the window is refreshed. This is useful in case you want to replace the display screen as a result of some other movement, and can be used to display animations, and so on.

WxMemoryDC lets in you to attract to a wxBitmap rather than to a window. The ensuing wxBitmap can be used for a ramification of factors, such as an off display buffer of what is on display screen.

WxBufferedDC and wxBufferedPaintDC are easy convenience lessons that derive from wxMemoryDC. You give it a buffer bitmap after which all drawing goes to the bitmap. When the final connection with the buffered dc is going out of scope or is deleted then the contents of the bitmap are dumped to the actual DC (if any) which you gave to the buffered dc whilst you constructed it. This allows to reduce flicker and such for complicated drawings. And additionally reduces the time needed for EVT_PAINT handlers due to the fact all they're doing is drawing the buffer bitmap, now not a whole complicated drawing. You can without difficulty do the equal aspect yourself without the buffered DCs with only a wxMemoryDC, a bitmap and a DrawBitmap name.

Django Interview Questions
Question 18. Why Doesn't The Getstring Method Of Wxcommandevent Work?

Answer :

Many simple controls like buttons, listing containers, take a look at bins, etc., generate a wxCommandEvent, because the occasion is frequently processed by means of the discern window, and best command events propogate to the parent (if the control itself does not cope with them). However, due to the fact the values wanted by the event handler range relying at the type of the manipulate and on the unique occasion, wxCommandEvent has a spread of various techniques for retrieving the price. Depending on the control and event, not a majority of these techniques will go back non-0 or non-empty values. For instance, GetString simplest works for EVT_LISTBOX and EVT_CHOICE, but doesn't make any feel for EVT_CHECKBOX. Read the documentation of the wxCommandEvent technique for details of which events aid that technique. If you need extra records, you'll want to retrieve a reference to the manipulate which generated the occasion (see How can my EVT_XYZ handler locate the manage that generated an occasion?)

C++ Interview Questions
Question 19. Why Do The Paths To My Resource Files Work In Testing, But Fail After Installation On Windows?

Answer :

This is a recognized trouble. In testing, the relative paths point to the documents efficiently, but after set up the relative paths do now not factor to the meant region. To remedy this, you may want to provide a dynamic absolute course to the aid files.

Insert the following code on your essential Python document:

import sys
import os.Direction
import __builtin__
# Sets the homepath variable (you may change the call) to the directory in which your application is positioned (sys.Argv[0]).
__builtin__.__dict__['homepath'] = os.Direction.Abspath(os.Course.Dirname(sys.Argv[0]))

Whenever you need to load a resource record, you need to append homepath as follows, the use of os.Course.Join(). Your utility will now load directory names successfully in both trying out and publish-set up.

Toolbar.AddSimpleTool(1, wx.Image(os.Path.Join(homepath, 'resfilenew.Png'), wx.BITMAP_TYPE_PNG).ConvertToBitmap(), 'New', '')

Django Tutorial
Question 20. How Can My Evt_xyz Handler Find The Control That Generated An Event?

Answer :

The occasion your handler receives might be of a category derived from wxEvent, which has a GetEventObject technique. In the case of an occasion generated by means of a manage, calling GetEventObject() at the occasion will go back a connection with the manage.

Lisp programming Interview Questions
Question 21. How Do I Embed Images In Python Code?

Answer :

Use img2py.Py from the tools folder of your wxPython installation. It converts an image report to .Png format, compresses it, and shops the binary records in a .Py report with workouts to load the picture.

Question 22. How Do I Keep Wxpython From Redirecting Errors And Exceptions To A Gui Window?

Answer :

Quoting from Getting Started

When a python application hits an unhandled exception (trojan horse!) on your program, it aborts with a traceback this is beneficial in locating the source of the trouble. WxPython programs do the identical, but with a twist. The traceback is routed to stdio, that is captured in a nice GUI frame impartial of your program. If an exception indicates up in an occasion handler, the traceback is displayed, and your application keeps on as satisfactory it is able to. BUT, if the exception occurs whilst initializing your program, the traceback will display up, after which your program will abort, taking the stdio window (and your traceback) with it before even the fastest reader can make sense of it.
You can keep stdio from being hijacked by using wxPython by means of supplying more than one optional parameters while you instantiate your wxApp. An example says it satisfactory:
Toggle line numbers

myapp = MyApp() # functions typically. Stdio is redirected to its personal window
myapp = MyApp(zero) #does not redirect stdout. Tracebacks will display up at the console.
Myapp = MyApp(1, 'filespec') #redirects stdout to the file 'filespec'
# NOTE: These are named parameters, so that you can try this for progressed readability:
myapp = MyApp(redirect = 1, filename = 'filespec') # will redirect stdout to 'filespec'
myapp = MyApp(redirect = 0) #stdio will stay at the console...
Ruby on Rails 2.1 Tutorial
Question 23. I Created A Sample Application With Some Controls But When I Reach The Last Control And Hit The Tab Key Again Focus Does Not Return To The First Control. What Is Wrong?

Answer :

Maybe you're the usage of the wxNotebook window. If you place a wxNotebook at once on a body tab order typically gets burdened. Try putting a wxPanel at the wxFrame and placed wxNotebook onto this panel. As a rule, honestly do not vicinity wxNotebook directly on a wxFrame (besides the body is a wxDialog?). If you operate a

WxDialog, tabbing have to work as expected. If you use a MDIChildFrame, you need to create a Panel first, after which positioned your controls on the Panel, no longer at once on the MDIChildFrame.

R Programming language Interview Questions
Question 24. What Does "unicode Build" Really Mean?

Answer :

Unicode in Python: There are some elements of unicode-ness to maintain music of here. First, in Python there are unicode gadgets and there are string items. String objects are essentially a sequence of 8-bit characters, and unicode gadgets are a series of "wide" characters (both 16-bit or 32-bit relying on platform and options used whilst constructing Python.) They are related to every different in that a unicode item may be encoded into a string object the use of a specific "codec" (a matched enCODer and DECoder pair). You can think about a codec as being just like the "magic decoder ring" that came inside the container of cereal whilst you had been a child, (or possibly whilst your dad changed into a child...) String gadgets can be decoded right into a unicode object the usage of the decoder part of the codec.

Unicode in wxWidgets: On the opposite side of the fence is wxWidgets and how it is able to use unicode. In the C++ code there is a class named wxString, and all string kind parameters and go back values inside the wxWidgets library use a wxString kind. The wxWidgets library has a unicode collect transfer that makes wxString be both an array of eight-bit characters (the C char statistics kind) or an array of wide characters (C's wchar_t information type.) So in other words you may have a wxWidgets construct in which wxStrings are unicode and some other construct in which wxStrings are ansi strings.

Unicode in wxPython: So what does all that imply for wxPython? Since Python does recognise approximately string and unicode gadgets, and you may have both inside the equal application, the wxPython wrappers need to try to do some thing intelligent based totally on if the wxWidgets getting used is an unicode construct or an ansi build.

So, if wxPython is using an ansi construct of wxWidgets then:

Return values from wx features and strategies might be string items.
Strings handed as parameters to wx functions and techniques will be used without conversion.
Unicode gadgets handed as parameters to wx functions and methods will first be transformed to a string item using the default encoding. You can use sys.Getdefaultencoding() to discover what the default encoding is. You may get an UnicodeEncodeError if there are characters in the unicode object which do not have an identical ordinal in the default encoding. To paintings around this you could convert the unicode object to a string your self the use of a extraordinary codec.
And if wxPython is the use of an unicode build of wxWidgets then:

Return values from wx features and strategies might be unicode items.
Strings passed as parameters to wx capabilities and strategies will first be transformed to a unicode object the usage of the default encoding. You can also get an UnicodeDecodeError exception if there are characters within the string that are not mapped to unicode ordinals with the aid of the default encoding. To work round this you may convert the string to unicode yourself using a selected codec.
Unicode objects exceeded as parameters to wx features and methods may be used with out conversion.
PHP Interview Questions
Question 25. What Is A Wxpython Release Series?

Answer :

The wxWidgets challenge has followed the release model utilized by the Linux Kernel task in which there are alternating sets of releases wherein one set are considered "solid" and the next set are considered "development." For wxWidgets "strong" and "improvement" do not talk to bugginess, however to the stability of the API and backwards compatibility.

Stable: For the length of the collection existing APIs aren't modified, although new non-virtual magnificence methods and such can be delivered. Binary compatibility of the C++ libs is maintained with the aid of no longer allowing any modifications that modify the in-memory length or layout of the classes and structs. This can and often does impose barriers on what sorts of improvements or computer virus fixes may be executed in a solid release series, however this virtually best impacts the C++ layer due to the fact in Python being backwards well matched has a slightly extraordinary connotations.
Development: The foremost cause of the development series of releases is to add new functionality or to correct issues that couldn't be corrected in a stable series due to binary compatibility problems, all as a way to create the next strong collection. So for the duration of the development collection present the APIs are allowed to be modified or removed as needed, despite the fact that most of the time C++ source-stage compatibility is maintained thru deprecated overloaded features or macros, and so on. For wxPython this often approach that there will be supply-degree incompatibilities because there is no overloading or macros, and on the way to help the new version of the API every now and then the old model must be eliminated.
Because of the binary compatibility troubles, the modern day development model of wxWidgets/wxPython can often be much less buggy than the trendy version of the ultimate solid release series. However there may be the alternate-off that the APIs can be changing or evolving between variations in the development collection.

Lisp programming Tutorial
Question 26. How Do The Version Numbers Work?

Answer :

For releases wxPython makes use of a 4 component version variety. While this appears lots like how model numbers are used in other Open Source initiatives, there are a few subtle variations. So for a few launch A.B.C.D you may deduce the following:

1. Release Series: The first  additives of the model wide variety (A.B) represent the release collection, and if the B issue is an excellent variety then it's miles a stable collection, if it is an extraordinary variety then it's miles an improvement release collection. For example, 2.Four, 2.6, and 2.8 are stable and the API is extra or much less frozen inside each series, and a couple of.3, 2.Five, and 2.7 are development and the API and functionality is allowed to exchange or evolve as wished.

Because of this there can be quite massive changes between one solid series to the next (say 2.4 to two.6) and this frequently throws humans off because in other tasks adjustments of that magnitute would have prompted the first element of the model wide variety to exchange. Instead you should think about the mixture of A.B as being the main variety of the model.

2. Release Number: The 1/3 factor of the version variety (C) represents one of the releases in a release series. For example, 2.5.Zero, 2.5.1, 2.Five.2, 2.Five.3... Are all releases within the 2.5 release series. (And in view that in this case it is an improvement collection then the API and capability of two.Five.3 has developed to be extraordinary in places than it was in 2.Five.0.) The C++ wxWidgets releases usually forestall here and simplest A.B.C releases are made.

3. Subrelease range, or wxPython launch: The fourth element of the version range (D) is used to symbolize a subrelease, or incremental releases betweeen the official wxWidgets releases. These releases consist of fixes for wxWidgets bugs that wxPython may have exposed, or minor enhancements which are crucial for wxPython. This isn't an arbitrary wxWidgets image, however as a substitute a examined version of the code with fixes and enhancements not but to be had from wxWidgets besides from the supply code repository.

It can occasionally be confusing to maintain music of the various size-associated attributes of a wx.Window, how they relate to each different, and the way they interact with sizers. This report will try to clear the fog a touch, and give a few simple factors of things.

BestSize: The nice length of a widget depends on what form of widget it is, and generally also on the contents of the widget. For example a wx.ListBox's first-class size can be calculated based totally on how many items it has, as much as a positive restrict, or a wx.Button's first-class size might be calculated based on its label size, however normally might not be smaller than the platform default button size (until a fashion flag overrides that). Get the picture? There is a special technique inside the C++ code referred to as DoGetBestSize() that a class needs to override if it wants to calculate its own high-quality size based on its content material. The default DoGetBestSize() is designed to be used in container home windows, along with wx.Panel, and works some thing like this:

if the window has a sizer then it is used to calculate the quality length.
If the window has layout constraints then this is used to calculate the satisfactory size.
If the window has kids then the first-rate length is ready to be big enough to reveal all the youngsters.
If there aren't any children then the window's min size may be used for the first-rate size.
If there's no min size, then the modern length is used for the quality length.
MinSize: The min size of a widget is a size that is usually explicitly set by way of the programmer both with the SetMinSize() method or the SetSizeHints() technique. Most controls will also set the min length to the scale given in the control's constructor if a non-default price is passed. Top-stage windows inclusive of wx.Frame will not permit the consumer to resize the body underneath the min length.

Size: The length of a widget can be explicitly set or fetched with the SetSize() or GetSize() methods. This length value is the scale that the widget is currently the use of on display and is the way to alternate the scale of some thing that isn't always being controlled with the aid of a sizer.

ClientSize: The purchaser length represents the widget's place inner of any borders belonging to the widget and is the region that can be drawn upon in a EVT_PAINT event. If a widget doesn't have a border then its consumer length is the same as its size.

Initial length: The initial length of a widget is the size given to the constructor of the widget, if any. As stated above maximum controls will also set this size value because the manage's min length. If the scale surpassed to the constructor is the default wx.DefaultSize, or if the scale isn't completely special (such as "length=(a hundred and fifty,-1)") then most controls will fill in the length the use of the excellent size and could set the initial length of the manipulate to the resulting length.

AdjustedBestSize: This value is calculated by way of taking the max of the widget's quality size and min length values and returning the end result. This has been eliminated in 2.7.2.

GetEffectiveMinSize: (formerly GetBestFittingSize) A blending of the widget's min size and excellent length, giving precedence to the min size. For instance, if a widget's min length is about to (150, -1) and the excellent size is (eighty, 22) then the fine becoming length is (a hundred and fifty, 22). If the minsize is (50, 20) then the excellent becoming length is (50, 20). This approach is what's known as through the sizers while determining what the necessities of each object within the sizer is, and is used for calculating the overall minimal desires of the sizer.

SetInitialSize(size): (previously SetBestFittingSize) This is a touch specific than the everyday size setters. Rather than just setting an "preliminary size" characteristic it really sets the minsize to the price passed in, blends that cost with the first-class length, after which sets the size of the widget to be the end result. So you can remember this approach to be a "Smart SetSize". This approach is what's referred to as by way of the constructor of maximum controls to set the minsize and preliminary length of the manipulate.

Window.Fit(): The Fit technique sets the scale of a window to in shape round its youngsters. If it has no youngsters then not anything is completed, if it does have kids then the size of the window is ready to the window's excellent length.

Sizer.Fit(window): This sets the dimensions of the window to be huge sufficient to house the minimal size wanted through the sizer, (at the side of some different constraints...) If the sizer is the one this is assigned to the window then this have to be equal to window.Fit().

Sizer.Layout(): Recalculates the minimum space needed with the aid of every object inside the sizer, after which lays out the gadgets within the area presently allotted to the sizer.

Window.Layout(): If the window has a sizer then it sets the distance given to the sizer to the present day size of the window, which ends up in a call to sizer.Layout(). If the window has layout constraints instead of a sizer then the limitations set of rules is administered. The Layout method is what's referred to as through the default EVT_SIZE handler for container windows.

Python Automation Testing Interview Questions
Question 27. Why Can't I Globally Catch Exceptions From Mainloop?

Answer :

One of the frequently asked questions for wxPython has to do with why you can't use a international exception handler wrapped round the decision to the app object's MainLoop method. To apprehend the answer to this query you need to remember that wxWidgets and the wxPython wrappers are C++ code and on every occasion an event handler or other callback is called you grow to be with every other layer of C++ and Python code on the stack. I generally consult with this because the C++/Python sandwich. For example:

You name MainLoop: that is a Python to C++ transition.
The user clicks a button and your EVT_BUTTON handler is called, which transitions back to Python
The handler calls self.SetSize, now we are returned in C++
You have a EVT_SIZE handler that is known as, which places us again in Python
The handler calls Layout(), again in C++
The Layout causes some other panel to get resized, and it has it's own EVT_SIZE handler, now we are back in Python once more.
That EVT_SIZE handler calls Update to pressure an instantaneous repaint of the panel, placing us back in C++
The handler for the EVT_PAINT is called, which places control at the Python facet once more.
C Interview Questions
Question 28. Why Doesn't A Sizer On A Wx.Window Work?

Answer :

probable a bit surprising to discover that it does not paintings in any respect. No format takes place. It's as though the sizer isn't there at all. There is a good reason for this, and there may be also a completely simple workaround.

The reason is that due to the fact that wx.Window is the base of the window hierarchy then adding auto-format support to wx.Window might imply that every widget could inherit it, even people who are not meant to be bins of different windows. For example it doesn't make much sense to have wx.CheckBox assist automobile-format capability as it will likely never have child widgets that it wishes to control.

The workaround is quite simple, just use a wx.Panel rather than a wx.Window. If for some purpose you do need to use a wx.Window and also deliver it a sizer, then virtually bind a handler for EVT_SIZE to the window too, and inside the occasion handler name self.Layout().

R Programming language Tutorial