text: import pandas as pd
  import os
  
  BASE = "/var/www/html/runs/"
  
  def readfile(year):
  	fname = BASE + "run{}_parcel_output.csv".format(runnum)
  	return pd.read_csv(fname, low_memory=False) \
  		if os.path.isfile(fname) else pd.DataFrame()
  
  df = pd.concat([
  	readfile(runnum)
      for runnum in range(1338, 1344)
  ], axis=0)
  
  df = df.query("(residential_units > 150 or job_spaces > 300) and SDEM != True")
  
  grps = df.groupby('geom_id')
  
  df = grps.first()
  df["occurences"] = grps.size()
  
  print len(df), df.occurences.describe()
  
  df.to_csv("large_projects.csv")
  