name 'A' is not defined : <p>I am trying to learn opencv using python, when I try to define a variable, I got the same error. </p>

<p>this is my code </p>

<pre><code>import numpy as np 
import cv2 

img = cv2. imread('love.jpg', 1)
cv2. imshow('image', img)

A == cv2.waitkey(0) &amp; 0xFF

if A == 27:
cv2.destroyAllWindows()

elif A ==   ord('s'):
cv2.imwrite('love.png', img)
cv2.destroyAllWindows()
</code></pre>

<p>and this is the result </p>

<pre><code>NameError: name 'A' is not defined
</code></pre>

<p>I thing the problem in installing python in my device ( windows 10, 64 bit)  </p>
