title: Finding the max and min in a tuple of tuples
body: <p>I'm new to python and having some problems finding the minimum and maximum values for a tuple of tuples. I need them to normalise my data. So, basically, I have a list that is a row of 13 numbers, each representing something. Each number makes a column in a list, and I need the <code>max</code> and <code>min</code> for each column. I tried indexing/iterating through but keep getting an error of </p>
  
  <pre><code>max_j = max(j)
  
  TypeError: 'float' object is not iterable
  </code></pre>
  
  <p>any help would be appreciated! </p>
  
  <p>The code is (assuming data_set_tup is a tuple of tuples, eg ((1,3,4,5,6,7,...),(5,6,7,3,6,73,2...)...(3,4,5,6,3,2,2...)) I also want to make a new list using the normalised values.</p>
  
  <pre><code>normal_list = []
  
  for i in data_set_tup:
  
      for j in i[1:]: # first column doesn't need to be normalised
          max_j = max(j)
          min_j = min(j)
          normal_j = (j-min_j)/(max_j-min_j)
          normal_list.append(normal_j)
      normal_tup = tuple(normal_list)
  </code></pre>