Select all csv files from a directory, and filter a specific column in kotlin android

Question

Good afternoon people! I have been facing a problem creating an Android app, and I would like to know if you can help me. I developed a program in python (tkinter), where the user selects the directory where the files are (there are .pssesion and .csv files, the user needs the csv). Once the directory is selected, all csv files are selected (in this case, the first 6 lines are deleted, and only the first 16 lines of column 5 are selected), finally, there is a transposition of the data to the horizontal, and the file names are added to the index, as printed(the link to test https://drive.google.com/drive/folders/1_h3QdCMiWQ9uVQh_DiUB2RFI_VTKZhaR?usp=drive_link):

Below is the function activated by the button in python

def dir_select():
    
    selected_dir = filedialog.askdirectory(title="Escolha a pasta")
    
    if not selected_dir:
        return
    os.chdir(selected_dir)
    
    csv_files = glob.glob('*csv')
    
    list_map = map(lambda filename:
                 pd.read_csv(filename, header=None, encoding="UTF-16 LE",
                             engine='python', sep=",", skiprows=[0, 1, 2, 3, 4, 5], 
                             nrows = 16, usecols=[4]), csv_files)

    
    list_file = list(list_map)
    df = pd.concat(list_file, axis=1, ignore_index=True).T
    
    #get the file name and add as index
    index = []
    for a in csv_files:
        if a.endswith('.csv'):
          index.append(a[:-4])
    
    df.index = index
    columns_names = ['I16', 'I15', 'I14', 'I13', 'I12', 'I11', 'I10', 'I9', 
                    'I8', 'I7', 'I6', 'I5', 'I4', 'I3', 'I2', 'I1']
    df.columns = columns_names
    print(df)

    return df

index              0            1            2           ...   15
2022-031853-07_1   123.543000   166.202000   223.808000   ...   8383.000000
2022-031853-07_2   122.386558   164.766866   222.529414   ...   8349.414025
2022-031853-07_3   123.130502   166.088386   224.333815   ...   8349.645300
KCL_1             1565.487225  1838.774695  2264.166823   ...  68266.129876
KCL_2             1522.474882  1800.673612  2209.711340   ...  69398.544797

I've tried several things using chatgpt and Bard, but I'm stuck here. I can access the directory, but it returns null or [ ]. how to rewrite this function for kotlin, correctly?

val button = findViewById<Button>(R.id.select_button)
        button.setOnClickListener {
            // Launch the document tree picker intent
            val intent = Intent(Intent.ACTION_OPEN_DOCUMENT_TREE)
            directoryPickerResultLauncher.launch(intent)
        }
    }

    private val directoryPickerResultLauncher =
        registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
            if (result.resultCode == Activity.RESULT_OK) {
                // Get the selected directory URI
                val uri = result.data?.data
                if (uri != null) {
                    selectedDirectoryUri = uri.toString()

                    // List files in the selected directory and filter by .csv extension
                    val selectedDirectory = File(uri.path!!)
                    val dataFiles = selectedDirectory.listFiles { file ->
                        file.isFile && file.name.endsWith(".csv")
                    }
                    println("Entrou aqui - 1 ")
                    println(selectedDirectory)
                    println(dataFiles)
                    // Process the selected files
                    handlingFiles(dataFiles)
                }
            }
        }

    private fun handlingFiles(dataFiles: Array<File>?): List<Map<String, String>> {
        val columnsNames = listOf(
            "I16", "I15", "I14", "I13", "I12", "I11", "I10", "I9",
            "I8", "I7", "I6", "I5", "I4", "I3", "I2", "I1"
        )

        val resultData = mutableListOf<Map<String, String>>()

        if (dataFiles != null) {
            for (file in dataFiles) {
                val csvData = mutableListOf<Map<String, String>>()

                csvReader().open(file) {
                    readAllAsSequence().forEach { row ->
                        val rowData = mutableMapOf<String, String>()
                        for ((index, value) in row.withIndex()) {
                            if (index < columnsNames.size) {
                                rowData[columnsNames[index]] = value
                            }
                        }
                        csvData.add(rowData)
                        println(rowData)
                    }
                }

                resultData.addAll(csvData)
            }
        }

        // Log the resultData
        for ((index, row) in resultData.withIndex()) {
            Log.d("CSV Data", "Row $index: $row")
        }

        return resultData
    }

    companion object {
        private const val REQUEST_DIRECTORY = 123
    }
}