Python:循环读取所有文本文件行

Question

我想逐行读取巨大的文本文件（如果找到“str”的行，则停止）。 如何检查是否到达文件结尾？

fn = 't.log'
f = open(fn, 'r')
while not _is_eof(f): ## how to check that end is reached?
    s = f.readline()
    print s
    if "str" in s: break

Answer 1

不需要在python中检查EOF，只需执行以下操作：

with open('t.ini') as f:
   for line in f:
       print line
       if 'str' in line:
          break

Why the ^{} statement：

It is good practice to use the with keyword when dealing with file objects. This has the advantage that the file is properly closed after its suite finishes, even if an exception is raised on the way.