--- a/data_manager/picard_index_builder.py	Wed May 27 15:13:19 2015 -0400
+++ b/data_manager/picard_index_builder.py	Tue Apr 04 18:12:10 2017 -0400
@@ -1,22 +1,22 @@
 #!/usr/bin/env python
-#Dan Blankenberg
+# Dan Blankenberg
+from __future__ import print_function
 
-import sys
+import optparse
 import os
-import optparse
 import subprocess
-
-from json import loads, dumps
-
+import sys
+from json import dumps, loads
 
 DEFAULT_DATA_TABLE_NAME = "picard_indexes"
 
+
 def get_id_name( params, dbkey, fasta_description=None):
-    #TODO: ensure sequence_id is unique and does not already appear in location file
+    # TODO: ensure sequence_id is unique and does not already appear in location file
     sequence_id = params['param_dict']['sequence_id']
     if not sequence_id:
         sequence_id = dbkey
-    
+
     sequence_name = params['param_dict']['sequence_name']
     if not sequence_name:
         sequence_name = fasta_description
@@ -24,8 +24,9 @@
             sequence_name = dbkey
     return sequence_id, sequence_name
 
+
 def build_picard_index( data_manager_dict, fasta_filename, params, target_directory, dbkey, sequence_id, sequence_name, data_table_name=DEFAULT_DATA_TABLE_NAME ):
-    #TODO: allow multiple FASTA input files
+    # TODO: allow multiple FASTA input files
     fasta_base_name = os.path.split( fasta_filename )[-1]
     prefix = os.path.splitext( fasta_base_name )[0]
     sym_linked_fasta_filename = os.path.join( target_directory, fasta_base_name )
@@ -34,44 +35,47 @@
     proc = subprocess.Popen( args=args, shell=False, cwd=target_directory )
     return_code = proc.wait()
     if return_code:
-        print >> sys.stderr, "Error building index."
+        print("Error building index.", file=sys.stderr)
         sys.exit( return_code )
     data_table_entry = dict( value=sequence_id, dbkey=dbkey, name=sequence_name, path=fasta_base_name )
     _add_data_table_entry( data_manager_dict, data_table_name, data_table_entry )
 
+
 def _add_data_table_entry( data_manager_dict, data_table_name, data_table_entry ):
     data_manager_dict['data_tables'] = data_manager_dict.get( 'data_tables', {} )
     data_manager_dict['data_tables'][ data_table_name ] = data_manager_dict['data_tables'].get( data_table_name, [] )
     data_manager_dict['data_tables'][ data_table_name ].append( data_table_entry )
     return data_manager_dict
 
+
 def main():
-    #Parse Command Line
     parser = optparse.OptionParser()
     parser.add_option( '-f', '--fasta_filename', dest='fasta_filename', action='store', type="string", default=None, help='fasta_filename' )
     parser.add_option( '-d', '--fasta_dbkey', dest='fasta_dbkey', action='store', type="string", default=None, help='fasta_dbkey' )
     parser.add_option( '-t', '--fasta_description', dest='fasta_description', action='store', type="string", default=None, help='fasta_description' )
     parser.add_option( '-n', '--data_table_name', dest='data_table_name', action='store', type="string", default=None, help='data_table_name' )
     (options, args) = parser.parse_args()
-    
+
     filename = args[0]
-    
+
     params = loads( open( filename ).read() )
     target_directory = params[ 'output_data' ][0]['extra_files_path']
     os.mkdir( target_directory )
     data_manager_dict = {}
-    
+
     dbkey = options.fasta_dbkey
-    
+
     if dbkey in [ None, '', '?' ]:
         raise Exception( '"%s" is not a valid dbkey. You must specify a valid dbkey.' % ( dbkey ) )
-    
+
     sequence_id, sequence_name = get_id_name( params, dbkey=dbkey, fasta_description=options.fasta_description )
-    
-    #build the index
+
+    # build the index
     build_picard_index( data_manager_dict, options.fasta_filename, params, target_directory, dbkey, sequence_id, sequence_name, data_table_name=options.data_table_name or DEFAULT_DATA_TABLE_NAME )
-    
-    #save info to json file
+
+    # save info to json file
     open( filename, 'wb' ).write( dumps( data_manager_dict ) )
-        
-if __name__ == "__main__": main()
+
+
+if __name__ == "__main__":
+    main()