Rocket UniData

Calling Python time module from MV user defined user exit

  • 1.  Calling Python time module from MV user defined user exit

    Posted 08-12-2020 03:27

    In the previous article “Dealing with the Python time module from Rocket MV BASIC” I showed how it is possible to access the python internal time module and convert the python date to string display format, then convert it back into the number of seconds since Epoch. 

     

    Python RESULT:
    python time= 1418146291
    Python RESULT:
    python local time= Tue Dec  9 09:31:31 2014
    Python RESULT:
    python time= 1418146291

     

    While it is possible to write a subroutine to handle the interaction between MV BASIC and Python, you can get more from you subroutine if you write it as a User Defined User Exit.

     

    User exits are the codes used in the ICONV and OCONV functions.  In the first article of this series we showed how we can call the u2py.DynArray.iconv and u2py.DynArray.oconv functions to convert display dates into internal format, and then convert back into display format:

     

    python> test = u2py.DynArray("04 Dec 2014")
    python> itest =  test.iconv("D")
    python> itest
    <u2py.DynArray value=b'17140'>
                  python> itest.oconv("D4/")
    <u2py.DynArray value=b'12/04/2014'>

     

    The limitation on the MV date conversion is that it only deals with the date.  There is a separate conversion code that deals with time.  The following user defined user exit calls the python module we worked with in the previous article, and exposes it to the MV Developer as a conversion code that handles timedate values.

     

    pyTimeDate
    SUBROUTINE Upytimedate( return_val, STATUS, input_val, TYPE )
    ***************************************************************
    *
    * Brief functional description
    * Example user exit to deal with Python time module
    * Copyright (c) 2020
    **************************************************************
    *
    * Detailed description
    *
    * Usage, such as return_val = OCONV(input_val,"UpyTimeDate")
    *
    **************************************************************
    * processing code area:
    * Arguments:
    *  return_val = final data to return.
    *  STATUS = 0 for success, other for failure.
    *  input_val= data to be converted or processed.
    *  TYPE: 0 for ICONV, 1 for OCONV.
    *
    ModuleName = "python_time"
    *  import the module
    pymodule = PyImport(ModuleName)
    IF @PYEXCEPTIONTYPE NE '' THEN
      return_val = "bad import"
    END
    IF TYPE THEN
    * OCONV
      A = input_val+ 0
      FuncName = "localtime"
      return_val = PyCallFunction(ModuleName, FuncName, A )
      IF @PYEXCEPTIONTYPE NE '' THEN
        return_val = "bad function call ":FuncName
      END
    END ELSE
    * ICONV
      B = input_val
      FuncName = "getepoch"
      return_val = PyCallFunction(ModuleName, FuncName, B )
      IF @PYEXCEPTIONTYPE NE '' THEN
        return_val = "bad function call ":FuncName
      END
    END
    RETURN
    END

     

    Note that this is a simple example that handles limited formats and does minimal error checking.  Yet it allows us to create a display formatted date from the internal python representation, which is the number of seconds from Epoch.

     

    UTEST
    TIMEDATE = 1418126116
    PRINT "START WITH ":TIMEDATE
    OUTDATE =  OCONV(TIMEDATE, "UpyTimeDate")
    PRINT "OUTDATE = ":OUTDATE
    INDATE = ICONV(OUTDATE, "UpyTimeDate")
    PRINT "BACK TO INTERNAL ":INDATE

    Another benefit of having the code as a user defined user exit is that it works in a dictionary item as well.

     

    SORT DICT PYTEST TYP LOC CONV MNAME FORMAT SM ASSOC BY TYP BY LOC BY @ID 14:03:47 Dec 09 2014 1
    @ID............ TYP LOC...... CONV        MNAME...... FORMAT SM ASSOC.....
     
    @ID             D           0             PYTEST         10L    S
    RAW             D           1                            10L    S
    pyTimeDate      D           1 Upytimedate                30L    S
                                     
    3 records listed

     

     

    LIST PYTEST pyTimeDate RAW 14:06:23 Dec 09 2014 1
    PYTEST.... pyTimeDate.................... RAW.......
     
    1          Tue Dec  9 03:55:16 2014       1418126116
    3          Thu Dec 11 11:28:36 2014       1418326116
    2          Wed Dec 10 07:41:56 2014       1418226116
    3 records listed

     

    While this is a simple example, there are countless uses for accessing python modules in this manner.  A quick search of python.org will surely show numerous modules that you may want to access to add additional information to your MV Query Reports.



    ------------------------------
    Michael Rajkowski
    Rocket Software
    ------------------------------