Mr X wrote: > > > Hi looking for help with what should be a fairly simple Python problem, > relating to VB inter-operability. > Got a great response from a fellow named Matt at [EMAIL PROTECTED], > pointed me in some good directions - some areas, concerns still foggy > on, the below thread is included.... any feedback on this simple dilemma > would be very appreciated.
You can use py2exe to make an executable from a python program. Or the VB program could invoke a command line like "python prog.py data.txt" without needing to use py2exe. You can also write COM servers in Python. Kent > > Thanks, > > D > > thread follows below; > > ------------------------------------ > > To: [EMAIL PROTECTED] > Subject: Problem with Python math functions and VB > Date: 3/30/2006 9:39:28 PM > Download Message Display Headers Printer Friendly > Previous | Next > > Wondering if you might either know how to solve the following. > > I've a background in Visual Basic, and am using an old version, 4.0, it > compiles to a smaller executable which I prefer. I find myself in an odd > situation, needing a very simple yet powerful capability of Python for a > VB app > Im working on. > > Simply, a large 300 digit number is divided by a smaller number ranging > from 1 to 3 digits. I.e; > > This large 300 digit number is generated as a string from the VB app, > and I want to input this somehow > from the VB app directly to Python for simple math operations. > > Where; x = 300 digit number, y = divisor ( say '37') > > > x / 37 > > I want to divide x by y but I want the remainder of this division to at > least 3 or 4 decimal places, so my Python script at the command line; > > x %y /y. = z > > So now I want to take the resultant, the full number plus its remainder, > and I want to round this number up > to the next highest number and divide it by the same constant; > > z rounded up to next highest number (never the lowest) > > so > > z /y = z Long > > Remove the 'L' at the end, round up the last digit of z = Z > > Then; > > Z %y /y. = a > > Then I want the last five digits of z (not Z) and a truncated at the > end, so the last digit before > the decimal point and the four digits past the decimal point printed to > a text file. > > I want to be able to open the text file with the VB app and use this > data as inputs. > ========== > > Ok, so here is my dilemma, I know VERY litle about Python and a fair bit > about VB. > > Ideally, I'd love to be able to simply have some extremely small > executable that just accepts inputs > does the calculations above and then spits out the outputs. If it were > possible to write some > simple lines of math code in Python and then compile these scripts in > Python to a Windows > compatible executable,that would be fantastic. > > If I could simply have my VB app, 'call' the name of the tiny Python > executable, and then the Python executable > just automatically looked for a named text file (created by the VB app) > and extracted the 300 digit number from this, then performed the calcs, > then spit this data out as a new text file name it created, which I > could then use the VB app to open and read from, THAT would be ideal. > > However, I don't know if Python can compile scripts to an exe? If it can > how could I find out how to do this? > > If it doesn't, how could I get VB to directly pass commands to the > Python command line and then automatically > extract the outputs? Shelling out from VB to Python would be tough to > the command line I think, since the Python command line uses the 'Edit / > Mark, Paste' approach to inserting, copy inputs, outputs and this would > be virtually untenable, as far as I can tell to automate in a VB shell > out routine. > > So basically, how the heck can I access Pythons ability to perform > simple calculations on very large numbers, easily, from within VB 4.0 ? > There must be a way, it seems like such a simple think to do, especially > since the actual math operations are so simple, straight forward, and > would never change..... > > Any ideas? > > > > ------ > Matthew, thanks for your response. > > <-----Original Message-----> > >From: Matthew Dixon Cowles > >Sent: 3/31/2006 9:41:18 AM > >To: [EMAIL PROTECTED] > >Cc: [EMAIL PROTECTED] > >Subject: Re: [Python-Help] Problem with Python math functions and VB > > >I'm sure that there's a way to do that, but I'm not familiar with > >Visual Basic and I don't know what inter-process communication > >facilities it offers. > > Is there a person or group you might direct me to that has worked with this > inter-process communication between VB and Python? > > >I don't think that Python is going to be able to do that for you out > >of the box. Hundreds of digits of floating-point precision is a lot. > > Could you explain that a bit more, sorry Im not sure what you mean > by 'out of the box' ? If I run the Python command line screen in windows > and manually type out a very large number, say 180 digits; where 'X' = > very large number; > > X %37 /37. > > returns what Im after, value wise..... but of course I don't want to do > this manually each time > for every dividend. > > >You might find that one of the Python modules that let you use an > >extended-precision library would do what you want. GMPY is one: > > >http://gmpy.sourceforge.net/ > > Hey, thats interesting, wonder if these modules can be operated on with > VB..... > > >> So now I want to take the resultant, the full number plus its > >> remainder, and I want to round this number up > >> to the next highest number and divide it by the same constant; > > > >That's easy enough. > > > >> I want to be able to open the text file with the VB app and use this > >> data as inputs. > > > >Python can write to a file without any trouble, so it that form of > >inter-process communication suits you, you shouldn't have much > >trouble. I assume that Visual Basic has an easy way to start a > >program and supply it with arguments, so you could have your Python > >program get its inputs from sys.argv. > > What is sys.argv ? Thats really good news. In fact, all I really need > for the moment is > a python executable that; > > ================ > PYTHON ALGORITHM ABSTRACT > > a) opens a text file > b) reads a string from the file, which is a very large number > c) performs simple arithmetic operations; > > X %37 /37. = y (four digit remainder after decimal point) > X /37 = w (quotient as long, the resulting output is stored as a > variable, the 'L' suffix tagged on the end of this resultant then gets > removed. > then the last digit in the quotient resultant string is increased in > value by one, rounded upwards = 'Z' > > then > > Z %37 /37. = a > > then, y and a are printed to a text file with hard returns between them. > Thats it, thats all I need to do. > =================== > >Alas, it's not going to be extremely small. There isn't a compiler > >from Python to machine code. Py2exe will bundle a Python program, > >with everything that it needs to run, into a single executable > >archive. But the archive isn't small. Py2exe is at: > > > >http://www.py2exe.org/ > > the most important thing is the functionality, I'll sacrifice size if I > have to. My guess is this should work based on your comments, because > perhaps all I really have to do is have VB dump out the value of the > Very large number, `180 to 300 digits or so', to a text file, which then > becomes the input data for the Python executable, and then if I simply > call the name of the Python executable from VB as an instance, > then the Python App runs, spits out the data as a new text file, then > the VB app goes and opens the new text file and reads in the values, > and voila! There it is. I'm pretty sure I can call the Python app from > VB....... the alternative to all this would be to try and feed Python > scripts > directly to Python from VB, which I have NO idea how to do or where to > begin.... and am guessing would be much more messy... > > I haven't programmed in Python, how would the "PYTHON ALGORITHM > ABSTRACT" I describe above look like, code wise? > Is this fairly easy for you to describe? > > >It may be that Python isn't the best solution for you here. Are there > >extended-precision libraries for Visual Basic? > > Alas, none that I know of that are reliable and not incredibly > expensive, been looking for years, plus Im hooped because I have to work > with VB 4.0 instead of 6 +, guh.... > > >Regards, > >Matt > > Matt..... good name, why do I always seem to get along with Matts, you > people keep popping up in my life and its always a blast! > > Best regards, > > D > > _______________________________________________________________ > Get the FREE email that has everyone talking at http://www.mail2world.com > Unlimited Email Storage POP3 Calendar SMS Translator Much More! > > > ------------------------------------------------------------------------ > > _______________________________________________ > Tutor maillist - Tutor@python.org > http://mail.python.org/mailman/listinfo/tutor _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
