Python -如何将文件对象拆分成一个单独的字符列表？

with open("file.txt", "r") as file:
    lines = file.readlines()
    characters = [char for line in lines for char in line.split()]

with open("file.txt", "r") as file:
    content = file.read()
    characters = [char for char in content.split()]

with open("file.txt", "r") as file:
    characters = [char for chunk in iter(lambda: file.read(4096), '') for char in chunk.split()]