title: Python: .append(0)
body: <p>I would like to ask what the following does in Python.
  It was taken from <a href="http://danieljlewis.org/files/2010/06/Jenks.pdf" rel="noreferrer">http://danieljlewis.org/files/2010/06/Jenks.pdf</a></p>
  
  <p>I have entered comments telling what I think is happening there. </p>
  
  <pre><code># Seems to be a function that returns a float vector
  # dataList seems to be a vector of flat. 
  # numClass seems to an int
  
  def getJenksBreaks( dataList, numClass ):
  
      # dataList seems to be a vector of float. "Sort" seems to sort it ascendingly
      dataList.sort() 
  
      # create a 1-dimensional vector 
      mat1 = []
  
      # "in range" seems to be something like "for i = 0 to len(dataList)+1)
      for i in range(0,len(dataList)+1):
  
          # create a 1-dimensional-vector?
          temp = []
          for j in range(0,numClass+1):
  
              # append a zero to the vector?
              temp.append(0)
  
          # append the vector to a vector??
          mat1.append(temp)
  </code></pre>
  
  <p>(...)</p>
  
  <p>I am a little confused because in the pdf there are no explicit variable declarations. However I think and hope I could guess the variables.</p>