if判断处理 and try 异常处理

001：
import os

if os.path.exists('note.txt'):
    data = open('note.txt')
    for each_line in data:
        if not each_line.find(':') == -1:
            (role, line_spoken) = each_line.split(':',1)
            print (role, end='')
            print ('said:', end='')
            print (line_spoken, end='')
    data.close()
else:
    print ('The data file is missing')

002：

import os

try:
    data = open('note.txt')
    for each_line in data:
        try:
            (role, line_spoken) = each_line.split(':',1)
            print (role, end='')
            print ('said:', end='')
            print (line_spoken, end='')
        except:
            pass
    data.close()
except:
    print ('The data file is missing')