syn region texZone start="\\begin{shellcode}" end="\\end{shellcode}\|%stopzone\>" contains=@Spell
syn region texZone start="\\begin{pythoncode}" end="\\end{pythoncode}\|%stopzone\>" contains=@Spell
syn region texZone start="\\begin{pythontexcode}" end="\\end{pythontexcode}\|%stopzone\>" contains=@Spell
