human
Solve the following python programming problem given the following code:
def pcrdup_mark(inbam, outbam, fragment = False, countfile = None) : 
    cur_pos = None 
    cur_reads = { 
        
} 
    total = 0 
    unique = 0 
    duplicates = 0 
    dup_list = set () 
    def callback(read) : 
        return ('%s, %s, %s - %s' % (total, unique, duplicates, read.qname)) 
for read in bam_iter (bamfile, callback = callback) : 
        if ((not read.is_paired) or read.is_read1) : 
            total += 1 
if read.is_unmapped : 
            __flush_cur_reads (cur_reads, outbam, inbam, countfile) 
            if outbam : 
                outbam.write (read) 
continue 
start_pos = (read.tid, read.pos) 
        if fragment : 
            dup_pos = (read.tid, inbam.pos, '') 
else : 
            dup_pos = (read.tid, read.pos, read.isize) 
if ((not cur_pos) or (start_pos != cur_pos)) : 
            __flush_cur_reads (cur_reads, outbam, inbam, countfile) 
            cur_pos = start_pos 
            cur_reads = { 
                
} 
            idx = 0 
if ((not fragment) and (read.mate_is_unmapped or (not read.is_paired) or (not read.is_proper_pair) or (read.isize < 0))) : 
            if (read.qname in dup_list) : 
                read.is_duplicate = True 
                dup_list.remove (read.qname) 
if outbam : 
                outbam.write (read) 
else : 
            if (dup_pos in cur_reads) : 
                duplicates += 1 
                if (not fragment) : 
                    dup_list.add (read.qname) 
cur_reads [dup_pos].append ((read.mapq, (- idx), read)) 
else : 
                unique += 1 
                cur_reads [dup_pos] = [(read.mapq, (- idx), read)] 
idx += 1 
__flush_cur_reads (cur_reads, outbam, inbam, countfile) 
    sys.stdout.write (('Total reads:\t%s
' % total)) 
    sys.stdout.write (('Unique reads:\t%s
' % unique)) 
    sys.stdout.write (('PCR duplicates:\t%s
' % duplicates)) 

    
    

    Fix the buggy line: dup_pos = (read.tid, inbam.pos, '')
assistant
#Here is Python code to fix the buggy line: dup_pos = (read.

dup_pos = (read.tid, read.pos, '')