rows.py

# simple csv reader
# copyright (c) 2016 Tim Menzies http://menzies.us
# all rights reserved, BSD 2-clause license
from __future__ import division,print_function
import sys,string,re, math
sys.dont_write_bytecode=True

def rows(file,prep       = None,
              whitespace = '[\n\r\t]',
              comments   = '#.*',
              sep        = ","
              ):
  """
  Walk down comma seperated values, 
  skipping bad white space and blank lines
  """
  doomed = re.compile('(' + whitespace + '|' +  comments + ')')
  with open(file) as fs:
    for line in fs:
      line = re.sub(doomed, "", line)
      if line:
        row = map(lambda z:z.strip(), line.split(sep))
        if len(row)> 0:
           yield prep(row) if prep else row

def csv(file):
  """
  Convert rows of strings to ints,floats, or strings
  as appropriate
  """
  def atoms(lst):
    return map(atom,lst)
  def atom(x)  :
    try: return int(x)
    except:
      try: return float(x)
      except ValueError: return x
  for row in rows(file, prep=atoms):
    yield row

if __name__ == '__main__':
  for row in csv('../data/weather.csv'):
    print(row)