Python 读取大文件 chunk(block_size) 的疑惑

生成一个 10 行的文本文件，每一行以 "\n" 结尾，统计行数为 10 。

def generate_file(): with open("line.log", "w") as f: for i in range(1, 10+1): f.write(f"Line is: your target line{i} to print\n") def chunked_file_reader(fp, block_size=4 * 1024): while True: chunk = fp.read(block_size) if not chunk: break yield chunk def get_line_count(fname): count = 0 with open(fname) as fp: for chunk in chunked_file_reader(fp): count += chunk.count("\n") return count generate_file() line_count = get_line_count("line.log"） # > 10 

block_size 亦或者说 buffering 传入的大小是每一行的长度，count 结果会变成 9 ，求解

def return_count(fname): count = 0 with open(fname) as fp: line = fp.readline() for chunk in chunked_file_reader(fp, len(line)): count += chunk.count("\n") return count generate_file() line_count = get_line_count("line.log"） # > 9