Integrating exception handling in Python 'with' [duplicate]

Question

A simple way to open a file and read its contents is using with:

with open ('file.txt', "r") as filehandle:
    contents = filehandle.read()

But that does not include excepting file opening errors in a way that a try/except would:

try:
    filehandle = open('file.txt', 'r')
    contents = filehandle.read()
except IOError:
    print('There was an error opening the file!')
    sys.exit()

Is there a way to integrate a failure message in the with statement so that it exits gracefully if the opening fails that would be done in fewer lines of code than the second example yet provide the same functionality? If not that, is there anything more elegant (or minimalist) than the second form?

Joran Beasley · Accepted Answer · 2014-11-14 17:32:39Z

0

from contextlib import contextmanager

@contextmanager
def safe_open(fname,mode):
    try:
        fh = open(fname,mode)
    except IOError:
        print "ERROR OPENING FILE :",fname
        sys.exit()
    else:
        yield fh
        try:
            fh.close()
        except:
            pass


with safe_open("nofile","rb") as f:
    f.write("blah")

Im not sure that its more elegant but meh ...

answered Nov 14, 2014 at 17:32

Joran Beasley

114k13 gold badges167 silver badges187 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

amphibient Over a year ago

this does not look very elegant

Joran Beasley Over a year ago

thats only because you see the implementation ... if you just do from util import safe_open ... then use it. then its pretty elegant ... (

Collectives™ on Stack Overflow

Integrating exception handling in Python 'with' [duplicate]

1 Answer 1

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Linked

Related