title: Count non-empty cells in pandas dataframe rows and add counts as a column
body: <p>Using Python, <strong>I want to count the number of cells in a row that has data</strong> in it, in a pandas data frame <strong>and record the count in the leftmost cell of the row</strong>.</p>
  
  <p><a href="https://i.stack.imgur.com/Xb4MC.png" rel="noreferrer"><img src="https://i.stack.imgur.com/Xb4MC.png" alt="Frame showing count column on left as requested"></a></p>