Problem passing arguments to a Python script

I have part of the script below and I tried calling the script using

./tsimplex.py --fstmod=chris.cmod --nxz=8x6 --varp=0.25

but am getting the error

option --fstmod must not have an argument

Any idea on how to fix this would be highly appreciated

#! /usr/bin/python

import getopt
import popen2
import sys
import types
import os

__author__="user"
__date__ ="$20-Nov-2010 17:43:52$"

def print_info():
    print ""
    print "-------------------------------------------------------------"
    print ""
    print "SCRIPT: ../Scripts/tsimplex.csh"
    print ""
    print "VERSION: %s"%(Version)
    print ""
    print "CREATED BY: CHRISTOPHER DIMECH"
    print ""
    print "PURPOSE: Runs Tommy tsimplex"
    print ""
    print "USAGE:"
    print ""
    print "   $s"%(print_usage(1))
    print ""
    print "WHERE:"
    print ""
    print "   (O)  fout.cmod       Best sound speed model found"
    print "   (O)  fout.back       Backup file for "
    print "   (O)  fout.expl       Exploration file"
    print "   (O)  fout.log        Log file with misfit values"
    print "   (I)  tpath           Path to TOMMY tsimplex"
    print "   (I)  fbase.base      Model dimensions file"
    print "   (I)  fdata.dat       Travel times file"
    print "   (I)  fstmod.cmod     Starting Sound Speed Model"
    print "   (I)  frestore.back   Restore population from a backup file"
    print "   (I)  ftag            Appends a tag to the output file names"
    print "   (I)  nxz             Model size to invert, e.g. 3x2"
    print "   (I)  varp            Sound speed variation allowed"
    print "   (I)  sigma0          "
    print "   (I)  maxiter         Number of iterations to perform"
    print "   (I)  vrb             Verbosity level for log file"
    print "                        vrb options = none, low, medium, high"
    print "   (I) -tpf             Create a tommy parameter file"
    print "   (I) -tee             "
    print "   (I) -usage           Details of the arguments"
    print "   (I) -help            Details on using this script"
    print ""
    print "EXAMPLES:"
    print ""
    print "-------------------------------------------------------------"
    print ""

def print_usage(asstring=0):
    arg1="../Scripts/tsimplex.csh"
    arg2="[-tpath=] [-base=fbase.base] [-data=fdata.dat]"
    arg3="[-fstmod=fstmod.vmod] [-restore=frestore.back -ftag=]"
    arg4="-nxz= -varp= -sigma= [-vrb=vrb] -tpf [-tee] [-usage] [-help]"
#    usage="$arg1 $arg2 $arg3 $arg4"
    usage="%s %s %s %s"%(arg1,arg2,arg3,arg4)

    if asstring == 0:
        print usage
    else:
        return usage

if __name__ == "__main__":

    x = "ls -lrt"
    os.system(x)

    Version="V03"
    tpath = None
    fbase = None
    fdata = None
    fstmod = None
    frestore = None
    ftag = None
    fsr = None
    frc = None
    frestoretag = None
    nxz = None
    varp = None
    sigma = None
    maxiter = None
    dtau = None
    mdacc = None
    mindist = None
    maxitertp = None
    vrb = None
    tpf = None
    tee = None
    usage = None
    eg = None
    help = None
    info = None

    long_opts = ['tpath',
    'fbase',
    'fdata',
    'fstmod',
    'frestore',
    'frestoretag',
    'nxz',
    'varp',
    'sigma',
    'maxiter',
    'dtau',
    'mdacc',
    'mindist',
    'maxitertp',
    'vrb',
    'tpf',
    'tee',
    'usage',
    'eg',
    'help',
    'info']

    try:
        optlist, args = getopt.getopt(sys.argv[1:], "", long_opts)

    except getopt.GetoptError, err:
        # print help information and exit:
        print str(err) # will print something like "option -a not recognized"
        print_usage()
        sys.exit(2)

    for opt, val in optlist:
        if opt == "--help":
            print_info()
            sys.exit()
        elif opt == "--eg":
            print_usage()
            sys.exit()
        elif opt == "--info":
            print_info()
            sys.exit()
        elif opt == "--usage":
            print_usage()
            sys.exit()
        elif opt == "--tpath":
            tpath = val
            print " -tpath = tpath"
            print " -tpath = ",val
            print ""
        elif opt == "--fbase":
            fbase = val.split('.base')[0]
            print " -fbase = fbase.base"
            print " -fbase = ",val
            print ""
        elif opt == "--fdata":
            fdata = val.split('.dat')[0]
            print " -fdata = fdata.dat"
            print " -fdata = ",val
            print ""
        elif opt == "--fstmod":
            fstmod = val.split('.cmod')[0]
            print " -fstmod = fstmod.cmod"
            print " -fstmod = ",val
            print ""
        elif opt == "--frestore":
            frestore = val
            print " -frestore = frestore.back"
            print " -frestore = ",val
            print ""
        elif opt == "--ftag":
            ftag = val
            print " -ftag = ftag"
            print " -ftag = ",val
            print ""
        elif opt == "--nxz":
            nxp = val.split('x')[0]
            nzp = val.split('x')[1]
            print " -nxz = nxz"
            print " -nxz = ",val
            print ""
        elif opt == "--varp":
             varpint = val.split('.')[0]
             varpfrc = val.split('.')[1]
             print " -varp = varp"
             print " -varp = ",val
             print ""
        elif opt == "--sigma":
            sigma = val
            print " -sigma = sigma"
            print " -sigma = ",val
            print ""
        elif opt == "--maxiter":
            maxiter = val
            print " -maxiter = maxiter"
            print " -maxiter = ",val
            print ""
        elif opt == "--dtau":
            dtau = val
            print " -dtau = dtau"
            print " -dtau = ",val
            print ""
        elif opt == "--mdacc":
            mdacc = val
            print " -mdacc = mdacc"
            print " -mdacc = ",val
            print ""
        elif opt == "--mindist":
            mindist = val
            print " -mindist = mindist"
            print " -mindist = ",val
            print ""
        elif opt == "--maxitertp":
            maxitertp = val
            print " -maxitertp = maxitertp"
            print " -maxitertp = ",val
            print ""
        elif opt == "--vrb":
            vrb = val
            print " -vrb = vrb"
            print " -vrb = ",val
            print ""
        elif opt == "--tpf":
            tpf = val
            print " -tpf"
            print ""
        elif opt == "--tee":
            tee = val
            print " -tee (Create tommy parameter file)"
            print ""
        else:
            print ""
            print "ERROR: Unrecognised argument,",opt
            print ""
            sys.exit(-1)

    # -------------------------------------------------------------------
    # USER HAS NOT ASKED FOR INFORMATION ABOUT THE USE OF THIS SCRIPT
    # 1. Exit script if argument not recognized
    # 2. Set appropriate defaults if options not set
    # -------------------------------------------------------------------