Read all files from the input folder and convert all words in them to baseform words and write files to the output folder.

voikko_baseform.py

import libvoikko
import json
import os

# Read all files from the input folder and convert all words in them to baseform words and write files to the output folder.

# brew install --cask voikkospellservice
# brew install libvoikko
# pip3 install libvoikko

v = libvoikko.Voikko(u"fi")

ignore_words = ["olla"]
folder_path = "input_path"
new_folder_path = "output_path"
new_file_postfix = ""

for filename in os.listdir(folder_path):
  if os.path.isfile(os.path.join(folder_path, filename)):
    with open(os.path.join(folder_path, filename), 'r') as original_file:
      txt = original_file.read()
      txt = txt.lower().replace(".", " ").replace(",", " ").replace("\n", " ")

      word_list = txt.split(" ")

      bf_list = []
      for w in word_list:
        voikko_dict = v.analyze(w)
        if voikko_dict:
          bf_word = voikko_dict[0]['BASEFORM']
        else:
          bf_word = w

        if len(bf_word) > 3 and bf_word not in ignore_words:
          bf_list.append(bf_word)

      new_filename = os.path.splitext(filename)[0] + new_file_postfix + os.path.splitext(filename)[1]

      with open(os.path.join(new_folder_path, new_filename), 'w') as new_file:
        new_file.write(json.dumps(bf_list))