minimal Python 3 port

doc/script/simple_stream.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 """\
 Simple g-code streaming script for grbl
 
@@ -53,14 +53,14 @@ s.flushInput()  # Flush startup text in serial input
 # Stream g-code to grbl
 for line in f:
     l = line.strip() # Strip all EOL characters for consistency
-    print 'Sending: ' + l,
+    print(f"Sending {l}", end="")
     s.write(l + '\n') # Send g-code block to grbl
     grbl_out = s.readline() # Wait for grbl response with carriage return
-    print ' : ' + grbl_out.strip()
+    print(' : ' + grbl_out.strip())
 
 # Wait here until grbl is finished to close serial port and file.
 raw_input("  Press <Enter> to exit and disable grbl.") 
 
 # Close file and serial port
 f.close()
-s.close()    
+s.close()