Aligns a list with spaces.

tabbed_vector

def tabbed_vector(v,tabs,DELIM=", ",LEFT="(",RIGHT="),"):
  """
  
  Adjusts left or right with spaces and inserts commas. 
  
      >>> tabbed_vector([1,2],[2,2])
      '(1 , 2 ),'
      >>> tabbed_vector([1,2],[4,4])
      '(1   , 2   ),'
      >>> tabbed_vector([1,2],[4,-4])
      '(1   ,    2),'
      >>> tabbed_vector(['abc',2],[5,-4])
      "('abc',    2),"
  
  Unicode strings take more space than old strings:
  
      >>> tabbed_vector([u'abcdef',7],[9,-4])
      "(u'abcdef',    7),"
  
  If columns don't fit, an exception is raised:
  
      >>> tabbed_vector(['abc'],[1])
      Traceback (most recent call last):
      ...
      Exception: Tab for column 0 is too small by 4 chars.
      >>>
  
  """
  
  SPACES="                                                                                  " 
  i = 0
  buf = []
  for e in v:
    t = tabs[i]
    r = repr(e)
    if len(r) > abs(t):
      raise Exception("Tab for column %s is too small by %s chars." % (i,len(r) - abs(t)))
    if t < 0:
      el = (("%s%s" % (SPACES,r))[t:])
    else: 
      el = (("%s%s" % (r,SPACES))[:t])
    buf.append(el)
    i = i + 1
  return "%s%s%s" % (LEFT,DELIM.join(buf),RIGHT)

# Example usage:

def tab_matrix(m,tabs):
  """

  >>> tab_matrix([["Apples",6],["Oranges",7],["Plums",300]],[9,-3])
  ['Apples'  |   6]
  ['Oranges' |   7]
  ['Plums'   | 300]

  """
  for v in m:
    print tabbed_vector(v,tabs,DELIM=" | ",LEFT="[",RIGHT="]")
    


if __name__ == "__main__":
  import doctest
  doctest.testmod()