Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.python > #196389
| Path | csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail |
|---|---|
| From | Cameron Simpson <cs@cskk.id.au> |
| Newsgroups | comp.lang.python |
| Subject | Re: Best use of "open" context manager |
| Date | Sun, 7 Jul 2024 11:08:33 +1000 |
| Lines | 24 |
| Message-ID | <mailman.10.1720315042.2981.python-list@python.org> (permalink) |
| References | <954c4ca8-cf37-4482-a1be-46d39cb503f9@btinternet.com> <ZonqkTYNCiNQRQSv@cskk.homeip.net> |
| Mime-Version | 1.0 |
| Content-Type | text/plain; charset=utf-8; format=flowed |
| Content-Transfer-Encoding | 8bit |
| X-Trace | news.uni-berlin.de TgMZMq8V9MkVSlYve9ftUA4dZrArmARXP0WrYOgfUkJQ== |
| Cancel-Lock | sha1:X7YktMXbn/I4ZyA+2ZW4VaQPwyM= sha256:YUnOnxrfZt9Bejsc1g3TstMzasYQKZUd1RTZ7zfkBbE= |
| Return-Path | <cameron@cskk.id.au> |
| X-Original-To | python-list@python.org |
| Delivered-To | python-list@mail.python.org |
| Authentication-Results | mail.python.org; dkim=none reason="no signature"; dkim-adsp=none (unprotected policy); dkim-atps=neutral |
| X-Spam-Status | OK 0.017 |
| X-Spam-Evidence | '*H*': 0.97; '*S*': 0.00; 'this:': 0.03; 'cc:addr :python-list': 0.09; 'cc:name:python': 0.16; 'from:addr:cs': 0.16; 'from:addr:cskk.id.au': 0.16; 'from:name:cameron simpson': 0.16; 'message-id:@cskk.homeip.net': 0.16; 'received:13.237': 0.16; 'received:13.237.201': 0.16; 'received:13.237.201.189': 0.16; 'received:cskk.id.au': 0.16; 'received:id.au': 0.16; 'received:mail.cskk.id.au': 0.16; 'remember,': 0.16; 'wrote:': 0.16; 'cc:addr:python.org': 0.20; 'returns': 0.22; 'code': 0.23; 'lines': 0.23; 'cc:2**0': 0.25; 'object': 0.26; 'header:User- Agent:1': 0.30; 'context': 0.32; 'header:In-Reply-To:1': 0.34; 'received:au': 0.35; 'file': 0.38; 'put': 0.38; 'skip:o 10': 0.61; 'here': 0.62; 'received:13': 0.64; 'received:userid': 0.66; 'forgot': 0.84; 'itself.': 0.84; 'rob': 0.84; 'subject:manager': 0.84; 'subject:open': 0.84 |
| Mail-Followup-To | Rob Cliffe <rob.cliffe@btinternet.com>, Python <python-list@python.org> |
| Content-Disposition | inline |
| In-Reply-To | <954c4ca8-cf37-4482-a1be-46d39cb503f9@btinternet.com> |
| User-Agent | Mutt/2.2.13 (2024-03-09) |
| X-BeenThere | python-list@python.org |
| X-Mailman-Version | 2.1.39 |
| Precedence | list |
| List-Id | General discussion list for the Python programming language <python-list.python.org> |
| List-Unsubscribe | <https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe> |
| List-Archive | <https://mail.python.org/pipermail/python-list/> |
| List-Post | <mailto:python-list@python.org> |
| List-Help | <mailto:python-list-request@python.org?subject=help> |
| List-Subscribe | <https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe> |
| X-Mailman-Original-Message-ID | <ZonqkTYNCiNQRQSv@cskk.homeip.net> |
| X-Mailman-Original-References | <954c4ca8-cf37-4482-a1be-46d39cb503f9@btinternet.com> |
| Xref | csiph.com comp.lang.python:196389 |
Show key headers only | View raw
On 06Jul2024 11:49, Rob Cliffe <rob.cliffe@btinternet.com> wrote:
>try:
> f = open(FileName) as f:
> FileLines = f.readlines()
>except FileNotFoundError:
> print(f"File {FileName} not found")
> sys.exit()
># I forgot to put "f.close()" here -:)
>for ln in File Lines:
> print("I do a lot of processing here")
> # Many lines of code here .....
What about this:
try:
f = open(FileName) as f:
except FileNotFoundError:
print(f"File {FileName} not found")
sys.exit()
with f:
... process the lines here ...
Remember, the `open()` call returns a file object _which can be used as
a context manager_. It is separate from the `with` itself.
Back to comp.lang.python | Previous | Next | Find similar | Unroll thread
Re: Best use of "open" context manager Cameron Simpson <cs@cskk.id.au> - 2024-07-07 11:08 +1000
csiph-web