python中FileNotFoundError的异常

Traceback (most recent call last):

    File "alice.py", line 3, in <module>

        with open(filename) as f_obj:

FileNotFoundError: [Errno 2] No such file or directory: 'alice.txt'

filename = 'alice.txt'

try:

    with open(filename) as f_obj:

        contents = f_obj.read()

except FileNotFoundError:

    msg = "Sorry, the file " + filename + " does not exist."

    print(msg)

Sorry, the file alice.txt does not exist.