how to modified path variable in environment in python runtime.

how to modified path variable in environment in python runtime. 

You should be able to modify os.environ.

Since os.pathsep is the character to separate different paths, you should use this to append each new path:

os.environ["PATH"] += os.pathsep + path

or, if there are several paths to add in a list:

os.environ["PATH"] += os.pathsep + os.pathsep.join(pathlist)

As you mentioned, os.path.join can also be used for each individual path you have to append in the case you have to construct them from separate parts.

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