human
Solve the following python programming problem given the following code:
def print_diff(a, b, difftype = 'unified', filename = None, fp = None) : 
    def write_tempfile(data, **kwargs) : 
        (fd, path) = tempfile.mkstemp (** kwargs) 
        try : 
            os.write (fd, bytestr (data)) 
finally : 
            os.close (fd) 
return path 
if (difftype == 'unified') : 
        print_unified_diff (write_tempfile, b, fromfile = filename, tofile = '', n = 3, fp = fp) 
else : 
        if (difftype == 'html') : 
            htmldiffer = difflib.HtmlDiff (tabsize = 4) 
            html = htmldiffer.make_file (unilines (a), unilines (b), fromdesc = filename, todesc = '', context = True, numlines = 2) 
            htmlfilename = write_tempfile (html, suffix = '.html', prefix = timestamp ()) 
            reporterror (('
open "%s"' % htmlfilename), fp = fp) 
else : 
            if (difftype == 'opendiff') : 
                outfilename = write_tempfile (b, suffix = '.pbxproj', prefix = timestamp ()) 
                reporterror (('
opendiff "%s" "%s"' % (filename, outfilename)), fp = fp) 
else : 
                raise ValueError (("Unknown difftype: '%s'" % difftype)) 

    
    

    Fix the buggy line: print_unified_diff (write_tempfile, b, fromfile = filename, tofile = '', n = 3, fp = fp)
assistant
#Here is Python program to fix the buggy line: print_unified_diff (write_tempfile, b, fromfile = filename, tofile = '', n = 3, fp = fp)
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print_unified_diff (a, b, fromfile = filename, tofile = '', n = 3, fp = fp)