The Python interpreter does an implicit "import site" on initialization. You can disable it using the -S option if/when you care about startup time. Here are

The Python interpreter does an implicit "import site" on initialization. You can disable it using the -S option if/when you care about startup time. Here are some numbers on my MacBook Pro: $ ./run.sh bash hello.sh median 0.002 $ ./run.sh python hello.py median 0.016 $ ./run.sh python -S hello.py median 0.008