<commit_before># Changelog

## 9.0.0 (unreleased)

- _Backwards-incompatible_: Rename `subcast` param of `env.dict` to `subcast_values` for consistency with `subcast_keys`.
- _Backwards-incompatible_: Remove variable proxying. Use variable expansion instead (see 8.1.0 release notes below)
  ([#175](https://github.com/sloria/environs/issues/175)).
- _Backwards-incompatible_: Drop support for marshmallow 2 and Python 3.5,
  which are both EOL ([#174](https://github.com/sloria/environs/issues/174)).

## 8.1.0 (2020-10-31)

Features:

- Add support for variable expansion, e.g. `MY_VAR=${MY_OTHER_VAR:-mydefault}` ([#168](https://github.com/sloria/environs/pull/168)).
  Thanks [gnarvaja](https://github.com/gnarvaja) for the PR.

Deprecations:

- Variable proxying using the `{{VAR}}` syntax is deprecated
  and will be removed in environs 9.0.0.
  Use variable expansion using `${VAR}` instead.

```bash
# Before
export MAILGUN_LOGIN=sloria
export SMTP_LOGIN={{MAILGUN_LOGIN}}

# After
export MAILGUN_LOGIN=sloria
export SMTP_LOGIN=${MAILGUN_LOGIN}
```

```python
from environs import Env

env = Env(expand_vars=True)

SMTP_LOGIN = env.str("SMTP_LOGIN")  # => 'sloria'
```
<commit_msg>Update issue link<commit_after># Changelog

## 9.0.0 (unreleased)

- _Backwards-incompatible_: Rename `subcast` param of `env.dict` to `subcast_values` for consistency with `subcast_keys`.
- _Backwards-incompatible_: Remove variable proxying. Use variable expansion instead (see 8.1.0 release notes below)
  ([#175](https://github.com/sloria/environs/issues/175)).
- _Backwards-incompatible_: Drop support for marshmallow 2 and Python 3.5,
  which are both EOL ([#174](https://github.com/sloria/environs/issues/174)).

## 8.1.0 (2020-10-31)

Features:

- Add support for variable expansion, e.g. `MY_VAR=${MY_OTHER_VAR:-mydefault}` ([#164](https://github.com/sloria/environs/issues/164)).
  Thanks [gnarvaja](https://github.com/gnarvaja) for the PR.

Deprecations:

- Variable proxying using the `{{VAR}}` syntax is deprecated
  and will be removed in environs 9.0.0.
  Use variable expansion using `${VAR}` instead.

```bash
# Before
export MAILGUN_LOGIN=sloria
export SMTP_LOGIN={{MAILGUN_LOGIN}}

# After
export MAILGUN_LOGIN=sloria
export SMTP_LOGIN=${MAILGUN_LOGIN}
```

```python
from environs import Env

env = Env(expand_vars=True)

SMTP_LOGIN = env.str("SMTP_LOGIN")  # => 'sloria'
```

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