读取结尾为空行的文件时出错

Question

I'm trying to read a file line by line and do some stuff. The problem is that if I add a bunch of blank lines to the end of the file, I'm getting an exception (list index out of range).

def check_ip(address):
  try:
    socket.inet_aton(address)
    return True
  except:
    return False

def myfunction:
    with open(filename, 'r') as f:
      for line in f.readlines():
        if not line: continue
        tokens = line.strip().split()
        if not check_ip( tokens[0]  ): continue
        // do some stuff

Answer 1

Your empty line test doesn't take into account whitespace.

Use:

if not line.strip(): continue

otherwise you end up with an empty tokens list for those lines.

You don't have to call str.strip() when also using str.split() with no arguments; that call already strips leading and trailing whitespace:

tokens = line.split()

Note that you don't need (nor want) to use f.readlines() ; you can iterate over the file object directly :

for line in f: