input: def generate_html_table(table_name: str, genre: str) -> str:
      """
      Generates an HTML table displaying information about the top 10 bestselling books in a specific genre from a given table.
      
      >>> generate_html_table('Books', 'Fantasy')
      '<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr><tr><td>{title1}</td><td>{author1}</td><td>{genre1}</td><td>{sales1}</td></tr><tr><td>{title2}</td><td>{author2}</td><td>{genre2}</td><td>{sales2}</td></tr>...</table>'
      """
output:     html = f'<table><tr><th>Title</th><th>Author</th><th>Genre</th><th>Sales</th></tr>'
      for i in range(1, 11):
          html += f'<tr><td>{{title{i}}}</td><td>{{author{i}}}</td><td>{{genre{i}}}</td><td>{{sales{i}}}</td></tr>'
      html += '</table>'
      return html