Script tool parameters for a file that can be created or appended.

SzymAdamowski

I'd like to assign path to some file (let's say it's a log file) in a script tool as a parameter. This file may already exist (some information might have been written and I don't want to lose it) or may not (then I want to create it).

Now - if I set Direction to Input in Tool Properties  -> Parameters - then it is only possible to point to existing file (it won't allow me to create a new name). If I set Direction to Output then I can create new file, but if I point to old one, it will automatically overwrite it (not what I want as I want to retain the contents of the file)

Is there any smart way to make the tool parameter to behave the way I want?

StaticK

Matrix glitched and the JeffK account was deleted...

Ok, sure. Didn't know that the Folder/File dialog was a requirement but with that, get the folder first using the Folder Datatype, then list the files for folder selected through the ToolValidator class. The user can select one from the list if it does exists or type in a file name if it doesn't exist. New files will have to be typed in- how would you select something that doesn't exist? You can include/exclude the returned files list by extension or name in the ToolValidator to narrow the selection down.

 

import os

class ToolValidator:
  # Class to add custom behavior and properties to the tool and tool parameters.

    def __init__(self):
        # set self.params for use in other function
        self.params = arcpy.GetParameterInfo()
        self.fileNames = []
        
    def initializeParameters(self):
        # Customize parameter properties. 
        # This gets called when the tool is opened.
        
        return

    def updateParameters(self):
        # Modify parameter values and properties.
        # This gets called each time a parameter is modified, before 
        # standard validation.
        
               
        if self.params[0].altered:
            fileFilter = self.params[1].filter # <- change this param to the country list parameter index.

            # use list comprehension and set to return a distinct list of file names.
            self.fileNames = [filenames for filenames in os.listdir(self.params[0].valueAsText) if os.path.isfile(os.path.join(self.params[0].valueAsText, filenames))]
           
            fileFilter.list = self.fileNames
        if self.params[1].altered:
            if self.params[1].valueAsText not in self.fileNames:
                self.fileNames.append(self.params[1].valueAsText)
                fileFilter.list = self.fileNames       
        return

    def updateMessages(self):
        # Customize messages for the parameters.
        # This gets called after standard validation.
        return

    def isLicensed(self):
    # set tool isLicensed.
        return True

    def postExecute(self):
        # This method takes place after outputs are processed and
        # added to the display.
        return

import os
"""
Script documentation

- Tool parameters are accessed using arcpy.GetParameter() or 
                                     arcpy.GetParameterAsText()
- Update derived parameter values using arcpy.SetParameter() or
                                        arcpy.SetParameterAsText()
"""
import arcpy


def script_tool(filePath, fileName):
    """Script code goes below"""
    arcpy.AddMessage(f'param1: {filePath} param2: {fileName}')
    outPath = os.path.join(filePath, fileName)
    
    file_type = 'w' if not os.path.exists(outPath) else 'a'
    
    with open(outPath, file_type) as tFile:
        tFile.write(f'hello dude\n')


if __name__ == "__main__":
    
    filePath = arcpy.GetParameterAsText(0) if arcpy.GetParameterAsText(0) else None
    fileName = arcpy.GetParameterAsText(1) if arcpy.GetParameterAsText(1) else None
    
    
    script_tool(filePath, fileName)