Is there any method to append path to environment variable 'PATH' in python

Question

I want to append the path to exists environment variable PATH using python script.

I have tried to use os.environ['path'] = 'C:\\foo\\bin:%PATH%' , but its deleting all the existing paths and creating 'C:\\foo\\bin:%PATH%' as new path value.

os.environ['path'] = 'C:\foo\bin:%PATH%'

Answer 1

You should be doing

  import os

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

Answer 2

In your code:

os.environ['path'] = 'C:\foo\bin:%PATH%

python does not know what to do with %PATH% in the string, but the old value of the PATH environment variable is accessible as os.environ['path'] , so you can simply do:

os.environ['path'] = 'C:\foo\bin;' + os.environ['path']

Answer 3

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.