cara menghapus file duplikat dari folder dengan python

def remove_duplicates(dir):
    unique = []
    for filename in os.listdir(dir):
        if os.path.isfile(filename):
            filehash = md5.md5(file(filename).read()).hexdigest()
            if filehash not in unique: 
                unique.append(filehash)
            else: 
                os.remove(filename)
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