Python 使用环境变量

Question

I'm new to programming, and right now I'm working in a small personal project that uses environment variables to create global variables through classes, files, threads, and flask pages in a extremely easier way.

But I do have some questions about how it will work on mine and other computers.

1. Do the " os.environ " and " os.getenv " work equally in all systems (windows, mac and linux)?
2. How about the character limit? I'm using a single variable to keep a json dictionary, so how much info can I put in there?
3. Is there a way to block the access to the environment variables? Is it normal in companies and universities to block the access to them?

Answer 1

1. yes they work same, nothing different is mentioned in official documentation.
2. char limit depends on your system specification. please refer: What is the max length of a python string?
3. to block the access to the env var you can use "deny" eg.

    Deny from env="users"