title: Python program doesn't write to output csv, everything else seems to work correctly
body: <pre><code>    from subprocess import check_output
  import csv, operator
  
  
  extinction_pct = operator.itemgetter('AOT 500','AOT 675','AOT 870','AOT 936','AOT 1020')
  
  with open('csv_export.csv') as f_csv:
      reader = csv.DictReader(f_csv)
      for row in reader:
          with open("INPUT", 'w') as f_in:
               f_in.write("&amp;INPUT\n")
               f_in.write("WLINF = 0.250\n")               #lower frequency value
               f_in.write("WLSUP = 4.0\n")                 #highest frequency value
               f_in.write("WLINC = 0.5\n")                     #wavelength increment
               f_in.write("IDAY = 289\n")                  #computing for a specific day
               #f_in.write("ALAT = {Lat}\n".format(**row))    # for Python versions less than 3.6
               f_in.write(f"ALAT = {row['Lat']}\n")          #latitude of the location
           #f_in.write("ALON = {Long}\n".format(**row))    # for Python versions less than 3.6
               f_in.write(f"ALON = {row['Long']}\n")          #longitude of the location
               f_in.write("IDATM = 3\n")                   #atmopsheric model 2 - mid latitude summer
               f_in.write("ISALB = 5\n")                         #surface albedo feature
               f_in.write("IAER = 5\n")                          #boundary layer aerosol type selection - 5 - user defined spectral dependance of BLA
               f_in.write("WLBAER = .500,.675,.870,.936,1.02\n") #wavelenght points for IAER
               f_in.write("WBAER = 5*0.9\n")                      #single scattering albedo
               f_in.write("GBAER = 5*0.8\n")                      #assymetric factor used with IAER
           #f_in.write("TIME = {sama]}\n".format(**row))    # for Python versions less than 3.6
               f_in.write(f"TIME = {row['sama']}\n")                       #Time in IST format (-5.30hr)
          #f_in.write("QBAER = {}\n".format(','.join(extinction_pct(row)))    # for Python versions less than 3.6
               f_in.write(f"QBAER = {','.join(extinction_pct(row))}\n") #extinction efficiency percentage
               f_in.write("ZOUT = 0.0,15.0\n")                         #TOA defining
               f_in.write("/\n")
            check_output('sbdart &gt;&gt; output1.csv',shell=True)  #slarrt is the program, and ouytput.csv is the output file
  </code></pre>
  
  <p>This is my code, with help from @wwii </p>
  
  <p>My last line, check_output csv doesnt write to my output file at all. What could be the issue?
  thanks</p>
  
  <p>sbdart is a program, that takes the INPUT file and outputs in the command line</p>