Tcl is the major scripting language used by all FPGA vendors, and sadly it doesn't look like it is going away. You can call Python from it, but FPGA developers (especially those Windows) will make a big fuss about installing an external tool, and should they install Python2 or Python3? Also, the major FPGA programming languages (vhdl and verilog) make tcl look great (or any other language, for that matter).