title: f string formatting for numpy array
body: <p>Here is my code snippets. It prints the means and the standard deviations from the image pixels. </p>
  
  <pre><code>from numpy import asarray
  from PIL import Image
  import os
  
  os.chdir("../images") 
  image = Image.open("dubai_2020.jpg")
  pixels = asarray(image) 
  pixels = pixels.astype("float32")
  means, stds = pixels.mean(axis=(0, 1), dtype="float64"), pixels.std(
      axis=(0, 1), dtype="float64")
  print(f"Means: {means:%.2f}, Stds: {stds:%.2f} ")
  </code></pre>
  
  <p>And the output is </p>
  
  <pre><code> File "pil_local_standard5.py", line 15, in &lt;module&gt;
      print(f"Means: {means:%.2f, %.2f, %.2f}, Stds: {stds:%.2f, %.2f, %.2f} ")
  
  TypeError: unsupported format string passed to numpy.ndarray.__format__
  </code></pre>
  
  <p>How do I define the f-strings format of the data in this case?</p>