如何在Python中从文件中逐个读取字符？

结合其他答案的优点，这里提供一种更加简洁快速且不易受长文件/行影响的解决方案：

import functools as ft, itertools as it

with open(path) as f:
    for c in it.chain.from_iterable(
        iter(ft.partial(f.read, 4096), '')
    ):
        print(c)

f = open('hi.txt', 'w')
f.write('0123456789abcdef')
f.close()
f = open('hej.txt', 'r')
f.seek(12)
print f.read(1) # This will read just "c"

os.system("stty -icanon -echo")
while True:
    raw_c = sys.stdin.buffer.peek()
    c = sys.stdin.read(1)
    print(f"Char: {c}")

def read_char(inputfile, buffersize=10240):
    with open(inputfile, 'r') as f:
        while True:
            buf = f.read(buffersize)
            if not buf:
                break
            for char in buf:
                yield char
        yield '' #handle the scene that the file is empty

if __name__ == "__main__":
    for word in read_char('./very_large_file.txt'):
        process(char)

#reading out the file at once in a list and then printing one-by-one
f=open('file.txt')
for i in list(f.read()):
    print(i)