import os
os.environ["CL"] = r'-Xcompiler "/wd 4819"'
ちなみに同じ手口でcl.exe用の環境変数を設定すると便利だ。
os.environ["INCLUDE"] = r"C:\Program Files (x86)\Windows Kits\10\include\10.0.10240.0\ucrt"
os.environ["Path"] += r"C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\BIN\amd64"