Python compatability issue - 'in <string>' requires character as left operand

I make no claims to know anything at all about writing Python scripts or programming in general, but I've been tasked with writing one anyway that will have to operate on a wide variety of Python versions. I wrote, and did my testing on versions 2.3, 2.4 and all went well. Version 2.2 though is giving me fits and my google-fu must be weak because I'm coming up short with an answer.

The section of code that's giving me problems:

commandnum = 0
for commandloop in arguments[0:]:
    if "java" in arguments[commandnum][0]:
        for argloop in arguments[commandnum]:
            if "Dcatalina.home" in argloop:
                instance = argloop.split("/")
            elif "-Xms" in argloop:
                xms = argloop.split("Xms")
            elif "-Xmx" in argloop:
                xmx = argloop.split("Xmx")
            elif "-XX:MaxPermSize" in argloop:
                permsize = argloop.split("=")
            elif "Dcatalina.base" in argloop:
                home = argloop.split("=")
                appdir = home[-1]+"/webapps"
                warfiles = []
                for war in os.listdir(appdir):
                    if fnmatch.fnmatch(war, '*.war'):
                        warfiles.append(war)
                thefiles = ",".join(warfiles)
        try:
            instance
        except NameError:
            instance = None
        if instance is not None:
            print "%s %s %s %s %s %s" % (instance[-2], xms[-1], xmx[-1], permsize[-1], appdir, thefiles)
    commandnum = commandnum + 1

I understand that this is UGLY and probably a BAD thing, but the error that I'm getting is in the string matching using 'in'. From what I gather by googling, in Python 2.2 you're limited to one character for string matching using 'in'. What is the equivalent way in 2.2 to match on a string?

Upgrading machines to a modern version of Python is out of the question.

Any help/abuse is appreciated. Try to be gentle as this is the first thing of any size I've written开发者_如何学运维 outside of shell scripts and MS Basic on my TRS-80 CoCo in 1981.

Try using str.find, which returns -1 if the substring cannot be found.

>>> s = "The quick brown fox"
>>> s.find("The")
0
>>> s.find("brown")
10
>>> s.find("waffles")
-1

You can always match using regular expressions. It's been a while since I used 2.2, so I can't recall if re is available, or if you need to go back to regex, but I'm sure the docs on the python site will go back far enough.

Update: it looks like re is available.