Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!news.albasani.net!feeder.news-service.com!newsfeed.xs4all.nl!newsfeed6.news.xs4all.nl!xs4all!post.news.xs4all.nl!not-for-mail Return-Path: X-Original-To: python-list@python.org Delivered-To: python-list@mail.python.org X-Spam-Status: OK 0.004 X-Spam-Evidence: '*H*': 0.99; '*S*': 0.00; 'subject:using': 0.04; 'function,': 0.07; "shouldn't": 0.07; '"""': 0.09; 'def': 0.13; '"="': 0.16; 'expression.': 0.16; 'guessing': 0.16; 'simplified': 0.16; 'skip:# 30': 0.16; 'subject:regex': 0.16; 'subject:file': 0.16; 'skip:r 30': 0.19; 'variable': 0.21; 'header:In-Reply-To:1': 0.22; 'e.g.': 0.22; 'values': 0.23; 'example': 0.24; 'extract': 0.25; 'received:209.85.161.46': 0.26; 'received:mail- fx0-f46.google.com': 0.26; 'message-id:@mail.gmail.com': 0.28; 'thanks.': 0.28; 'received:209.85.161': 0.29; 'string': 0.29; 'hi,': 0.29; 'probably': 0.30; 'pattern': 0.31; 'whitespace': 0.31; 'match': 0.31; 'import': 0.32; 'to:addr:python-list': 0.32; '...': 0.32; 'expression': 0.33; 'martin': 0.33; 'lines': 0.34; 'regular': 0.34; 'file': 0.35; 'print': 0.35; 'replacement': 0.35; 'some': 0.37; 'however': 0.37; 'received:209.85': 0.37; 'received:google.com': 0.38; 'anything': 0.38; 'to:addr:python.org': 0.39; 'received:209': 0.39; 'would': 0.40; 'header:Received:5': 0.40; 'split': 0.60; 'unwanted': 0.60; 'best': 0.60; 'and,': 0.63 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:content-type; bh=CGQYZrSRM5pK0RYkww2sw3jy8P2OfRVRKQMCYk/GqQc=; b=m1z+nUjN7zM9XUbYPKPFwtEOjFZVognAsPuCLuY0/YJxmig411uVJkBdjTCuKjEF04 7b4gUr47ERw+EbsY0Vws+Jy1aAWx1z3bn6rRKAMUMJC7YBsrnx3lsIIg3U1VlNCg/dGc 0rkb2WJYq/hhyNg5n1cFaii6y90JRlxS5hPd0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Jz5Ba+BpkP9arbXxiezfT+nCCbxsp7fAbn6rNgZQTPi34BEsoHXMpo9oLjzunqMItj G34twOLEXZLW3mSOIrdiC2PlD3WZm6kQwZ2OgN8CIkCG5O98njrw4j+jpqDInIy0Lv/7 P55FhcOur3IlzqtMOmOZMFECVMEnA+GF606f0= MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 5 Apr 2011 10:32:11 +0200 Subject: Re: replace regex in file using a dictionary From: Vlastimil Brom To: python-list@python.org Content-Type: text/plain; charset=ISO-8859-1 X-BeenThere: python-list@python.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: General discussion list for the Python programming language List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Newsgroups: comp.lang.python Message-ID: Lines: 51 NNTP-Posting-Host: 82.94.164.166 X-Trace: 1301992333 news.xs4all.nl 81476 [::ffff:82.94.164.166]:52254 X-Complaints-To: abuse@xs4all.nl Xref: x330-a1.tempe.blueboxinc.net comp.lang.python:2639 2011/4/5 Martin De Kauwe : > Hi, > > So i want to replace multiple lines in a text file and I have reasoned > the best way to do this is with a dictionary. I have simplified my > example and broadly I get what I want however I am now printing my > replacement string and part of the original expression. I am guessing > that I will need to use a more complicated expression than I am > currently am to achieve what I want? > > my aim is to match the expression before the "=" and replace the > string after the equals... > > My failed example... > [...] > > thanks. > -- > Hi, I guess, you would have to split the line and extract the substrings before and after "=" and replace only the value part. Or you can use regular expression replace with a replacement function, e.g. like the following sample. The re pattern would probably need some tweaking to match the variable names, the values and the whitespace around "="; and, of course, it shouldn't match anything unwanted in the original text ... hth, vbr #################################### import re orig_str = """structcn = 150.0 metfrac0 = 0.85 unknown7 = 38.2 """ replacement_dict = {"structcn": "999.0", "metfrac0": "0.85"} def repl_fn(m): return m.group(1) + m.group(2) + replacement_dict.get(m.group(1), m.group(3)) new_str = re.sub(r"([\w\d_]+?)( = )([\d.-]+)", repl_fn, orig_str) print new_str ####################################