Lazy coding for the win

Published on 2016-01-30 by Tess

Its been a while since I wrote any new hook scripts so I thought I would refresh my knowledge before talking about them at phpconference.co.uk. I also love playing around with python - it's straight forward, pretty and gives good 'sad puppy' feedback when you've missed a closing bracket.

So I came up with this beast to turn svn log output into a dictionary. You can then do what you like with it: output to a file, turn into html, stream to a feed, whatever.


    from subprocess import check_output
    
    repo_cmd = "svn log file:///svnrepro/tests/deleteFile/trunk"
    output = check_output(repo_cmd, shell=True)
    
    demarker = "--------------------------------------------------------\"
    contents = output.split(demarker)
    
    ignore_these = ["[hotfix]", "[merge]"]
    
    log_book = list()
    
    for section in contents:
        lines = section.split("\\")
        if len(lines) < 2 : continue
        commit_info = lines[0]
        message = lines[1].strip()
        ignore = False
        for prefix in ignore_these:
            if message.startswith(prefix):
                ignore = True
                break
        if ignore == True: continue
        info = commit_info.split("|")
        section = dict()
        section["revision"] = info[0].strip().replace("r", "")
        section["user"] = info[1].strip()
        section["date"] = info[2].strip()
        length = info[3].strip().split(" ")
        section["messageLength"] = length[0]
        section["message"] = message
        log_book.append(section)
    
    print log_book

What can I say, I like understanding things at a first principles level.

Of course then I remembered a cool flag which turns a predetermined text output into something much more meaningful.


    repo_cmd = "svn log --xml file:///svnrepro/tests/deleteFile/trunk"

xml.etree.ElementTree is the built in python way of handling xml and, again, it's a bit hand cranked and leads to many unnecessary lines of code. So why re-invent the wheel?

"Has someone already done this?" is rapidly becoming my first question, and yes, someone has!

https://github.com/martinblech/xmltodict

This is the second module library I tried, and is one that can actually deal with lists of elements - essential for svn log output. If you are used to handling things in JSON, it's really easy:


    from subprocess import check_output
    import json
    import xmltodict
    # https://github.com/martinblech/xmltodict
    
    repo_cmd = "svn log --xml file:///svnrepro/tests/deleteFile/trunk"
    
    output = check_output(repo_cmd, shell=True)
    
    print json.dumps(xmltodict.parse(output))

I have to admit, a little piece of me feels like I'm no longer writing 'real' code and that there's nothing left unsolved or uncoded. The rest of me is doing a happy dance - now we are freed up to use technology to solve the real issues - save time, collaborate well and communicate effectively to make lives better!