title: Calculating the average of a column in a list in Python
body: <p>I have to calculate the average of each column in a specific nested list and then save the average into a new list. In my code so far, I have set the original list into a nested list and transposed it to read in the columns. I am just not sure how to code the average.</p>
  
  <pre><code>#First open the data text file
  import re
  
  f = open('C:\Python27\Fake1.txt', 'r')
  
  #Convert to a nested list
  nestedlist = []
  q = f.read()
  f.close()
  numbers = re.split('\n', q) #Splits the \n and \t out of the list
  newlist = []
  for row in numbers:
     newlist.append(row.split('\t'))
  
  
  #Reading in columns
  def mytranspose(nestedlist):
     list_prime = []
     for i in range(len(nestedlist[0])):
            list_prime.append([])
     for row in nestedlist:
            for i in range(len(row)):
                   list_prime[i].append(row[i])
     return(list_prime)
  print (mytranspose(newlist))
  
  
  #Average of Columns
  def myaverage(nestedlist):
     avg_list = []
     a = 0
     avg = 0
     for i in newlist:
            a = sum(newlist[i])
            avg = a/len(row)
            avg_list.append(avg[i])
     return(list_prime)
  
  print(myaverage(newlist))
  </code></pre>