Calling Python Scripts from Basic

Calling Python scripts from Office Basic macros is possible, and valuable features can be obtained such as:

ComputerName identification or OSName detection are possible,
Basic FileLen() function and com.sun.star.ucb.SimpleFileAccess.getSize() API function exhibit a 2 Gigabytes file size upper limit that Python helps to overcome,
com.sun.star.util.PathSettings can be normalized,
and many more.

A reasonable exposure to Office Basic and to Application Programming Interface (API) features is recommended prior to perform inter-language calls from Basic to Python, to JavaScript or any other script engine.

Retrieving Python Scripts

Python scripts can be personal, shared, or embedded in documents. In order to execute them, Office Basic needs to be provided with Python script locations. Locating com.sun.star.script.provider.XScript interface compliant UNO objects allows the execution of Python scripts:


         Option Explicit
             
         Public Function GetPythonScript(macro As String, -
                 Optional location As String) As com.sun.star.script.provider.Xscript
             ''' Grab Python script object before execution
             ' Arguments:
             '    macro   : as "library/module.py$macro" or "module.py$macro"
             '    location: as "document", "share", "user" or ENUM(eration)
             ' Result:
             '    located com.sun.star.script.provider.XScript UNO service'''
             If IsMissing(location) Then location = "user"
             Dim mspf As Object ' com.sun.star.script.provider.MasterScriptProviderFactory
             Dim sp As Object ' com.sun.star.script.provider.XScriptProvider compatible
             Dim uri As String
             If location="document" Then
                 sp = ThisComponent.getScriptProvider()
             Else
                 mspf = CreateUNOService("com.sun.star.script.provider.MasterScriptProviderFactory")
                 sp = mspf.createScriptProvider("")
             End If
             uri = "vnd.sun.star.script:"& macro &"?language=Python&location="& location
             GetPythonScript = sp.getScript(uri)
         End Function ' GetPythonScript

Executing Python Scripts

The Office Application Programming Interface (API) Scripting Framework supports inter-language script execution between Python and Basic, or other supported programming languages for that matter. Arguments can be passed back and forth across calls, provided that they represent primitive data types that both languages recognise, and assuming that the Scripting Framework converts them appropriately.

Syntax

workstation-name = script.invoke(Array(), Array(), Array())

opSysName = script.invoke(Array(), in-outs, Array()) ' in-out is an Array

file-len = script.invoke(Array(systemFilePath), Array(), Array())

normalizedPath = script.invoke(Array(systemFilePath), Array(), Array())

Embedded Scripts Examples

Below ComputerName, and GetFilelen routines are calling their Python counterparts, using aforementioned GetPythonScript function. Exception handling is not detailed.


         Option Explicit
         Option Compatible ' Properties are supported
             
         Private scr As Object ' com.sun.star.script.provider.XScript
             
         Private Property Get ComputerName As String
             '''Workstation name'''
             scr = GetPythonScript("Platform.py$computer-name", "document")
             ComputerName = scr.invoke(Array(), Array(), Array())
         End Property ' ComputerName
             
         Private Function GetFilelen(systemFilePath As String) As Currency
             '''File size in bytes'''
             scr = GetPythonScript("Os/Path.py$get-size", Script.ISEMBEDDED)
             GetFilelen = scr.invoke(Array(systemFilePath), Array(), Array(),)
         End Function ' GetFilelen
             
         Private Type -SCRIPT-LOCATION
             ISEMBEDDED As String ' document script
             ISPERSONAL As String ' user script
             ISSHARED As String ' Office macro
         End Type ' -SCRIPT-LOCATION
             
         Public Function Script() As Object ' Text enumeration
             Static enums As -SCRIPT-LOCATION : With enums
             If .ISEMBEDDED = "" Then
                 .ISEMBEDDED = "document" ' document script
                 .ISPERSONAL = "user" ' user scripts
                 .ISSHARED = "share" ' Office macro
             End If : End With ' enums
             Script = enums
         End Function ' Script

Two different Python modules are called. They can either be embedded in the current document, either be stored on the file system. Argument type checking is skipped for clarity:

Platform.py


         # -*- coding: utf-8 -*-
         from --future-- import unicode-literals
          
         import platform
          
         def computer-name() -> str:
             return platform.node()
          
         def OSname() -> str:
             return platform.system()

Os/Path.py


         # -*- coding: utf-8 -*-
         from --future-- import unicode-literals
          
         import os.path
          
         def get-size(systemFilePath: str) -> str:
             return str(os.path.getsize(systemFilePath))
          
         def normalyze(systemPath: str) -> str:
             return os.path.normpath(systemPath)

Personal or Shared Scripts Examples

The calling mechanism for personal or shared Python scripts is identical to that of embedded scripts. Library names are mapped to folders. Computing Office user profile and shared modules system file paths can be performed as detailed in Getting session information. Below OSName, HelloWorld and NormalizePath routines are calling their Python counterparts, using aforementioned GetPythonScript function. Exception handling is not detailed.


         Option Explicit
         Option Compatible ' Properties are supported
             
         Private scr As Object ' com.sun.star.script.provider.XScript
             
         Private Property Get OSName As String
             '''Platform name as "Linux", "Darwin" or "Windows"'''
             scr = GetPythonScript("Platform.py$OSname", Script.ISPERSONAL)
             OSName = scr.invoke(Array(), Array(), Array()) 
         End Property ' OSName
             
         Private Sub HelloWorld()
             '''Office Python shared sample'''
             scr = GetPythonScript("HelloWorld.py$HelloWorldPython", Script.ISSHARED)
             scr.invoke(Array(), Array(), Array(),)
         End Sub ' HelloWorld
             
         Public Function NormalizePath(systemFilePath As String) As String
             '''Strip superfluous '..' in path'''
             scr = GetPythonScript("Os/Path.py$normalyze", "user")
             NormalizePath = scr.invoke(Array(systemFilePath), Array(), Array())
         End Function ' NormalizePath

Python standard modules

Office embedded Python contains many standard libraries to benefit from. They bear a rich feature set, such as but not limited to:

argparse Parser for command-line options, arguments and sub-commands
cmath Mathematical functions for complex numbers
csv CSV files reading and writing
datetime Genuine date and time types
json JSON encoder and decoder
math Mathematical functions
re Regular expression operations
socket Low-level networking interface
sys System-specific parameters and functions
unittest and trace Unit testing framework and Track Python execution
xml.etree.ElementTree ElementTree XML API