Using pysrt to convert a SRT file to a list of sentences.

STR_to_Sentences.py

import pysrt
import os

output_folder_name = "txt"

try:
    os.mkdir("./{}".format(output_folder_name))
except OSError:
    pass  # already exists

for file in os.listdir("."):
    if file.endswith(".srt"):

        print("Converting: ", file)

        output_name = file.split('.')[0] + ".txt"

        subs = pysrt.open(file)

        sentences = []
        line = ""

        for sub in subs:

            # +' ' because some sentences span over multiple time stamps
            line += str(sub.text).replace('\n', ' ') + ' '

            for letter in line:
                # finding end of sentence
                if letter == ".":

                    # saving sentence and removing any new line characters
                    sentences.append(line.replace('\n', ' '))
                    line = ""

        with open(os.path.join("./{}/".format(output_folder_name) + output_name), encoding='utf-8', mode='w') as output_file:
            output_file.writelines("%s\n" % sentence for sentence in sentences)