Print list of objects to stdout

print_table_to_stdout.py

from collections import Counter

def table(data, fields, user_config={}, debug=False):
  """Nicely formatted table, for printing to stdout
  
  Required:
  @param data: list, objects instances
  @param fields: list, object properties/fields to display
  
  Optional:
  @param user_config: dict, overriding auto config: 
                            specify "field" => {..options..}, e.g.
                              options = {
                                'player_in': {
                                  'max_length': 10,
                                  'align': 'center',
                                  'format': fn_name
                                }
                              }
  @param debug: bool, show steps
  
  """ 
  # Set default config
  config = {
      field: {
          'max_length': None,
          'align': None,
          'format': getattr(builtin, 'unicode'),
        } for field in fields
    }

  # Merge configs
  for field in fields:
    
    # Override from user
    if field in user_config:
      config[field].update(user_config[field])
    
    # Max width of field value in chars
    if not config[field]['max_length']:
      config[field]['max_length'] = max(
          [len(field)] + 
          [len(config[field]['format'](getattr(row, field))) 
            for row in data]
        )
      
    # Alignment based on most common var type
    if not config[field]['align']:
      types = [type(config[field]['format'](getattr(row, field))) for row in data]
      groups = Counter(types)
      data_type = groups.most_common(1)[0][0]
      config[field]['align'] = "rjust" if data_type in [int, float] else "ljust"
              
  # Output strings    
  trs = []
  data.insert(0, fields) # throw fields list back in
  for i, row in enumerate(data):
    tds = []
    for field in fields:
      value = field.upper() if i==0 else config[field]['format'](getattr(row, field))
      max_length = config[field]['max_length']
      align = "center" if i==0 else config[field]['align']
      td = getattr(unicode(value)[:max_length], align)(max_length)
      tds.append(td)      
    trs.append('  '.join(tds))
  
  # Combine rows, add line
  total_width = sum([config[field]['max_length'] for field in fields]) + 2*(len(fields)-1) # add space at end for the col separators
  table = trs[:1] + ["-"*total_width] + trs[1:]     
  return '\n' + '\n'.join(table) + '\n'