Set C/C++ compiler for Python extensions
 I would like to setup a default C and C++ compiler when building Python extensions under Linux.  I noticed the --compiler option to python setup.py build, but I am wondering if there is a way of setting this as an environmental variable so that I can specify them just once.  
It's not possible to use an environment variable, but you can create a setup.cfg file. See Writing the Setup Configuration File. The following setup.cfg file will try to use the Intel C Compiler:
[build_ext] 
compiler=icc
