How to access environment variable values?
Actually it can be done this way:
import os
for item, value in os.environ.items():
print('{}: {}'.format(item, value))
Or simply:
for i, j in os.environ.items():
print(i, j)
For viewing the value in the parameter:
print(os.environ['HOME'])
Or:
print(os.environ.get('HOME'))
To set the value:
os.environ['HOME'] = '/new/value'
Environment variables are accessed through os.environ
:
import os
print(os.environ['HOME'])
To see a list of all environment variables:
print(os.environ)
If a key is not present, attempting to access it will raise a KeyError
. To avoid this:
# Returns `None` if key doesn't exist
print(os.environ.get('KEY_THAT_MIGHT_EXIST'))
# Returns `default_value` if key doesn't exist
print(os.environ.get('KEY_THAT_MIGHT_EXIST', default_value))
# Returns `default_value` if key doesn't exist
print(os.getenv('KEY_THAT_MIGHT_EXIST', default_value))
To check if the key exists (returns True
or False
)
'HOME' in os.environ
You can also use get()
when printing the key; useful if you want to use a default.
print(os.environ.get('HOME', '/home/username/'))
where /home/username/
is the default