Text-based game engine

import os
import sys
import glob
import time

STORYFILE = "Story"

class StoryManager():
    def __init__(self, story):
        self.story = story
        self.currentChapter = 0

        self.endMessage = "The End"
        self.ended = False #Flag to check whether story has ended

    def getChapter(self):
        if self.currentChapter < len(self.story):
            return self.story[self.currentChapter]
        else:
            self.ended = True
            return self.endMessage

    def nextChapter(self):
        self.currentChapter += 1

        if self.currentChapter <= len(self.story):
            return self.story[self.currentChapter - 1]
        else:
            self.ended = True
            return self.endMessage

    def pollChoices(self, choices):

        chosen = ""

        while True:
            chosen =  input("Will you " + (" or ".join([choice[0] for choice in choices])) + " : ").lower()

            for choice in choices:
                if chosen == choice[0]:
                    print(choice[1])
                    return choice[1]


    def goThroughStoryLinearly(self):
        while not self.ended:
            next = self.nextChapter()
            delayedPrint(next[1], 50)
            self.pollChoices(next[2])

    def goThroughStory(self):
        while not self.ended:
            next = self.getChapter()
            delayedPrint(next[1], 100)
            self.currentChapter = self.pollChoices(next[2])

def delayedPrint(message, delay = 0):
    for char in message:
        print(char, end = "")
        sys.stdout.flush()
        time.sleep(delay / 1000)

def parseChapter(chapter):
    """Should fix"""

    try:
        choices = chapter[1][chapter[1].index("[") : chapter[1].index("]") + 1]
        return eval(choices), choices
    except Exception as e:
        print("Invalid choices in file", str(chapter[0]), ":", str(e))

def parseStory(story):
    chapters = []

    for item in story.items():
        choices = parseChapter(item)
        if choices:
            chapters.append((item[0], item[1].replace(choices[1], ""), choices[0]))

    return chapters

def startup():
    if not os.path.exists(STORYFILE):
        raise IOExeption("Story files missing")

def loadStoryFiles(fileExtension = ".txt"):
    story = {}

    for file in glob.glob(STORYFILE + "/*.txt"):
        f = open(file)
        chapter = file.replace("\\", "").replace(STORYFILE, "").replace(fileExtension, "")

        try:
            chapter = int(chapter)
        except ValueError:
            print("Non-numerical chapter name ignored")
            continue

        story[chapter] = f.read()
        f.close()

    return story

def main():
    startup()
    sm = StoryManager(parseStory(loadStoryFiles()))
    sm.goThroughStory()

if __name__ == "__main__":
    main()