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Solve the following python programming problem given the following code:
def main() : 
    INFO = 'Verilog module signal/module dataflow analyzer' 
    VERSION = pyverilog.utils.version.VERSION 
    USAGE = 'Usage: python example_dataflow_analyzer.py -t TOPMODULE file ...' 
    def showVersion() : 
        print (INFO) 
        print (VERSION) 
        print (USAGE) 
        sys.exit () 
optparser = OptionParser () 
    optparser.add_option ('-v', '--version', action = 'store_true', dest = 'showversion', default = False, help = 'Show the version') 
    optparser.add_option ('-I', '--include', dest = 'include', action = 'append', default = [], help = 'Include path') 
    optparser.add_option ('-D', dest = 'define', action = 'append', default = [], help = 'Macro Definition') 
    optparser.add_option ('-t', '--top', dest = 'topmodule', default = 'TOP', help = 'Top module, Default=TOP') 
    optparser.add_option ('--nobind', action = 'store_true', dest = 'nobind', default = False, help = 'No binding traversal, Default=False') 
    optparser.add_option ('--noreorder', action = 'store_true', dest = 'noreorder', default = False, help = 'No reordering of binding dataflow, Default=False') 
    (options, args) = optparser.parse_args () 
    filelist = args 
    if options.showversion : 
        showVersion () 
for f in filelist : 
        if (not os.path.exists (directives)) : 
            raise IOError (('file not found: ' + f)) 
if (len (filelist) == 0) : 
        showVersion () 
analyzer = VerilogDataflowAnalyzer (filelist, options.topmodule, noreorder = options.noreorder, nobind = options.nobind, preprocess_include = options.include, preprocess_define = options.define) 
    analyzer.generate () 
    directives = analyzer.get_directives () 
    print ('Directive:') 
    for dr in sorted (directives, key = (lambda x : str (x))) : 
        print (dr) 
instances = analyzer.getInstances () 
    print ('Instance:') 
    for (module, instname) in sorted (instances, key = (lambda x : str (x [1]))) : 
        print ((module, instname)) 
if options.nobind : 
        print ('Signal:') 
       ...

    
    

    Fix the buggy line: if (not os.path.exists (directives)) :
assistant
#Here is Python program to fix the buggy line: if (not os.

if (not os.path.exists (f)) :