Path: csiph.com!fu-berlin.de!uni-berlin.de!not-for-mail From: Malcolm Greene Newsgroups: comp.lang.python Subject: Technique for safely reloading dynamically generated module Date: Thu, 21 Jul 2016 10:42:21 -0400 Lines: 31 Message-ID: References: <1469112141.379402.672830825.05659985@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable X-Trace: news.uni-berlin.de 07qGlMD6Sgn3LTokAzG90QfxIaJTh/ERhAdzUROgAiVA== Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.003 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'received:internal': 0.09; 'subject:module': 0.09; 'python': 0.10; 'file,': 0.15; 'compile,': 0.16; 'from:addr:python': 0.16; 'language)': 0.16; 'malcolm': 0.16; 'message-id:@webmail.messagingengine.com': 0.16; 'missing,': 0.16; 'received:10.202': 0.16; 'received:10.202.2': 0.16; 'received:66.111': 0.16; 'received:66.111.4': 0.16; 'received:io': 0.16; 'received:messagingengine.com': 0.16; 'received:psf.io': 0.16; 'reload': 0.16; 'sys.path': 0.16; 'true:': 0.16; 'runs': 0.18; 'visible': 0.22; 'code.': 0.23; 'import': 0.24; 'module': 0.25; "we're": 0.30; 'code': 0.30; 'run': 0.33; 'source': 0.33; 'file': 0.34; 'server': 0.34; 'step': 0.36; 'there': 0.36; 'created': 0.36; 'to:addr:python-list': 0.36; 'received:10': 0.37; 'associated': 0.38; 'received:66': 0.38; 'version': 0.38; 'thank': 0.38; 'application': 0.39; 'to:addr:python.org': 0.40; 'header :Message-Id:1': 0.61; 'our': 0.64; 'techniques': 0.65; 'dsl': 0.84; 'of?': 0.84 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=bdurham.com; h= content-transfer-encoding:content-type:date:from:message-id :mime-version:subject:to:x-sasl-enc:x-sasl-enc; s=mesmtp; bh=wf9 JlLV6XyIZTWvRE9Mfns5IMBI=; b=Knf+M4ru/Qry0dlfrEwsaciEB8kPXM+7xp/ NcvQdM54z8ydUaWMWDWlJXWKLuIXIqdBshOAIwM97jtuSsfSwctxZKFzXaZgTu8S 0LZBOmlhMJncIEi8+2vcppz2BXSNg6uR6R4kCL5oEFvKIlQ9kNhs1lUc5y2OReRC lKTpjyCc= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-sasl-enc :x-sasl-enc; s=smtpout; bh=wf9JlLV6XyIZTWvRE9Mfns5IMBI=; b=K1fss F66GUVJ9Ww/W77+yOts0A8AdQNgCeZ5mv6HaafTZ+Mospp8/exmkf96KwLa8kb7+ x2itLIjFwjxIuqifxkOpmgeFEbCeBS3Q/Nr15TTnqvfNb7C7GOhY5qHeipjFJ66H OBYYEP7TpnR91FqlbNFbTBviGjpQmtjWAcPMiY= X-Sasl-Enc: Sri+p4pJll5wRGX1jvjPR6oqdM8Ljq3bNMf2l2WzgU5w 1469112141 X-Mailer: MessagingEngine.com Webmail Interface - ajax-2ccfea0a X-Content-Filtered-By: Mailman/MimeDel 2.1.22 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Mailman-Original-Message-ID: <1469112141.379402.672830825.05659985@webmail.messagingengine.com> Xref: csiph.com comp.lang.python:111715 We're designing a server application that parses a custom DSL (domain specific language) source file, generates a Python module with the associated logic, and runs the associated code. Since this is a server application, we need to reload the module after each regeneration. Is this process is simple as the following pseudo code or are there other issues we need to be aware of? Are there better techniques for this workflow (eval, compile, etc)? =20 We're working in Python 3.5.1. import importlib =20 # custom_code is the module our code will generate - a version of this # file will always be present # if custom_code.py is missing, a blank version of this file is created # before this step import custom_code =20 while True: # (re)generates custom_code.py visible in sys.path generate_custom_code( source_file ) =20 # reload the module whose source we just generated importlib.reload( custom_code ) =20 # run the main code in generated module custom_code.go() =20 Thank you, Malcolm =A0