ass="op">.</span><span class="nam">append</span><span class="op">(</span><span class="fst">f"</span><span class="fst">L </span><span class="op">{</span><span class="nam">x0</span> <span class="op">+</span> <span class="nam">tile_size</span><span class="op">}</span><span class="fst">,</span><span class="op">{</span><span class="nam">y0</span> <span class="op">+</span> <span class="nam">tile_size</span> <span class="op">-</span> <span class="op">(</span><span class="nam">r</span> <span class="key">if</span> <