# Python: Access Environment Variables With os.getenv

> Access environment variables in Python using os.environ like a dictionary, or use os.getenv with a default fallback value to avoid a KeyError exception

**URL:** https://sentry.io/answers/access-environment-variables-in-python/

---

## The Problem

How do I access environment variables in Python?

## The Solution

The Python `os` module contains a mapping object (similar to a dictionary) called [`environ`](https://docs.python.org/3/library/os.html#os.environ) that stores all environment variables and their values.

```python
import os

print(os.environ) # show all environment variables and their values.
```

One way to access environment variables is to use `os.environ` like a dictionary. For example, `os.environ['SHELL']` will contain the value of the `SHELL` environment variable. However, if the requested environment variable does not exist, trying to access it will raise a [`KeyError`](https://docs.python.org/3/library/exceptions.html#KeyError) exception. Therefore, a safer way to do this is use the `os.getenv` function, which allows us to specify a default fallback value.

```python
shell_ev = os.getenv('SHELL', '/bin/bash')
```

This code will store the value of the `SHELL` environment variable in `shell_ev`. If this environment variable does not exist, the string `/bin/bash` will be stored.

---

*Source: [sentry.io/answers/access-environment-variables-in-python/](https://sentry.io/answers/access-environment-variables-in-python/)*