title: How do I call to a line in a data file?
body: <p>I need to load data from a .txt file, but I cannot figure out how to refer to the rows and columns that I want. </p>
  
  <p>I have normally used code such as follows:</p>
  
  <pre><code>a = []
  b = []
  
  for line in file:
   if line[0] != 'x':
  
      False
   else:
      fields = (line.strip()).split('\t')
      a.append(fields[0])
      b.append(fields[1])
  </code></pre>
  
  <p>My issue is that the lines with the data I want do not all start with the same character like other files I have opened. The first line of data I want begins with a float (0.0) and goes up to 5300.0. This is column a. It is separated by a tab from the second column I need, b.</p>