title: How do I generate files for parametric analysis using EPPY
body: <p>I have successfully generated the first set of runs which changes just a single value from a base file. However, when I try to generate further runs for each run in the initial list (idfs) it only generates twos set of files rather than looping through each of the previously generated files.</p>
  <pre><code>import eppy
  import sys
  import os
  import numpy as np
  pathnameto_eppy = 'c:/eppy'
  pathnameto_eppy = '../'
  sys.path.append(pathnameto_eppy)
  
  from eppy import modeleditor
  from eppy.modeleditor import IDF
  
  iddfile = &quot;C:\EnergyPlusV9-5-0\PreProcess\IDFVersionUpdater\V9-5-0-Energy+.idd&quot;
  fname1 = r&quot;C:\Users\Breto\Documents\007 Python Programs\001 Parametrics\OPA OPT South_Shades 90_degrees.idf&quot;
  print(iddfile)
  IDF.setiddname(iddfile)
  EPW=r&quot;C:\\Users\\Breto\\Documents\\007 Python Programs\\001 Parametrics\\CAN_ON_Toronto.716240_CWEC.epw&quot;
  idf_init=IDF(idfname=fname1,epw=EPW)
  
  shade1=idf_init.idfobjects['WindowMaterial:SimpleGlazingSystem'][0]
  print(shade1)
  
  para_1_valRange=list(np.arange(0.1,1,0.1))
  para_1_numruns=int(len(para_1_valRange))
  print(para_1_numruns)
  print(para_1_valRange)
  
  os.chdir(r&quot;C:\\Users\\Breto\Documents\\007 Python Programs\\001 Parametrics\\&quot;)
  dir=os.getcwd()
  print(dir)
  idfs=[]
  
  for i in range(0,para_1_numruns,1):
      idf_l=idf_init
      glazing=idf_l.idfobjects['WindowMaterial:SimpleGlazingSystem'][0]
      glazing.Solar_Heat_Gain_Coefficient = para_1_valRange[i]
      idfs.append(idf_l)
      idf_l.saveas('OPA {} SHGC.idf'.format(para_1_valRange[i]))
  
  
  para_2_valRange=np.arange(50,95,5)
  print(para_2_valRange)
  idfs_2=[]
  for idf in idfs:
      for i in range(0,len(para_2_valRange),1):
          shade2=idf.idfobjects['Shading:Overhang'][0]
          shade3=idf.idfobjects['Shading:Overhang'][1]
          shade2.Tilt_Angle_from_WindowDoor=para_2_valRange[i]
          shade3.Tilt_Angle_from_WindowDoor=para_2_valRange[i]
          x=idf.idfobjects['WindowMaterial:SimpleGlazingSystem'][0]
          y=x.Solar_Heat_Gain_Coefficient
          idfs_2.append(idf)
          idf.saveas('OPA {} SHGC_ShadeAngle.idf'.format((y,para_2_valRange[i])))
  </code></pre>