def read_line(path):
  with open(path, 'r', encoding='utf-8') as fout:
    line = fout.readline()
    while line:
      line = fout.readline()
      print(line)

def read_size(path):
  with open(path, "r", encoding='utf-8') as fout:
    while 1:
      buffer = fout.read(8 * 1024 * 1024)
      if not buffer:
        break
      print(buffer)

from itertools import islice
def read_itertools(path):
  with open(path, 'r', encoding='utf-8') as fout:
    list_gen = islice(fout, 0, 5) # 两个参数分别表示开始行和结束行
    for line in list_gen:
      print(line)