# cabina
[](https://codecov.io/gh/nikitanovosibirsk/cabina)
[](https://pypi.python.org/pypi/cabina/)
[](https://pypi.python.org/pypi/cabina/)
[](https://pypi.python.org/pypi/cabina/)
## Installation
```sh
pip3 install cabina
```
## Usage
```python
import cabina
from cabina import computed, env
class Config(cabina.Config):
class Main(cabina.Section):
API_HOST: str = env.str("API_HOST", default="localhost")
API_PORT: int = env.int("API_PORT", default=8080)
@computed
def API_URL(cls) -> str:
return f"http://{cls.API_HOST}:{cls.API_PORT}"
```
```python
assert Config.Main.API_URL == "http://localhost:8080"
assert Config["Main"]["API_URL"] == "http://localhost:8080"
```
### print
```python
print(Config)
# class <Config>:
# class <Main>:
# API_HOST = 'localhost'
# API_PORT = 8080
# API_URL = 'http://localhost:8080'
```
## Recipes
* [Root Section](#root-section)
* [Computed Values](#computed-values)
* [Default Values](#default-values)
* [Raw Values](#raw-values)
* [Custom Parsers](#custom-parsers)
* [JSON Parser](#json-parser)
* [Prefetch Env Vars](#prefetch-env-vars)
* [Env Vars Prefix](#env-vars-prefix)
* [Inheritance](#inheritance)
### Root Section
```sh
export API_HOST=localhost;
export API_PORT=8080;
```
```python
import cabina
from cabina import env
class Config(cabina.Config, cabina.Section): # <- inherited from cabina.Section
API_HOST = env.str("API_HOST")
API_PORT = env.int("API_PORT")
assert Config.API_HOST == "localhost"
assert Config.API_PORT == 8080
```
### Computed Values
```sh
export API_HOST=localhost;
export API_PORT=8080;
```
```python
import cabina
from cabina import computed, env
class Config(cabina.Config, cabina.Section):
API_HOST: str = env.str("API_HOST")
API_PORT: int = env.int("API_PORT")
@computed
def API_URL(cls) -> str:
return f"http://{cls.API_HOST}:{cls.API_PORT}"
assert Config.API_URL == "http://localhost:8080"
```
### Default Values
```sh
export API_HOST=127.0.0.1;
```
```python
import cabina
from cabina import env
class Config(cabina.Config, cabina.Section):
API_HOST = env.str("API_HOST", default="localhost") # <- default arg
API_PORT = env.int("API_PORT", default=8080)
assert Config.API_HOST == "127.0.0.1"
assert Config.API_PORT == 8080
```
### Raw Values
```sh
export DEBUG= yes;
# ^ extra space
```
```python
import cabina
from cabina import env
class Config(cabina.Config, cabina.Section):
DEBUG_RAW = env.raw("DEBUG") # <- alias to env("DEBUG")
DEBUG_STR = env.str("DEBUG")
assert Config.DEBUG_RAW == "" # True
assert Config.DEBUG_STR == "yes" # Error
```
### Custom Parsers
```sh
export HTTP_TIMEOUT=10s;
```
```python
import cabina
from cabina import env
from pytimeparse import parse as parse_duration # <- external package
class Config(cabina.Config, cabina.Section):
HTTP_TIMEOUT: int = env("HTTP_TIMEOUT", parser=parse_duration)
assert Config.HTTP_TIMEOUT == 10
```
### JSON Parser
```sh
export IMAGE_SETTINGS='{"AllowedContentTypes": ["image/png", "image/jpeg"]}';
```
```python
import json
import cabina
from cabina import env
class Config(cabina.Config, cabina.Section):
IMAGE_SETTINGS = env("IMAGE_SETTINGS", parser=json.loads) # <- json.loads
assert Config.IMAGE_SETTINGS == {
'AllowedContentTypes': ['image/png', 'image/jpeg']
}
```
### Prefetch Env Vars
```sh
export DEBUG=yes;
export API_PORT=80a; # <- extra "a"
```
```python
import cabina
from cabina import env
class Config(cabina.Config, cabina.Section):
DEBUG = env.bool("DEBUG")
API_HOST = env.str("API_HOST")
API_PORT = env.int("API_PORT")
Config.prefetch() # <- prefetch method
# ConfigEnvError: Failed to prefetch:
# - Config.API_HOST: 'API_HOST' does not exist
# - Config.API_PORT: Failed to parse '80a' as int
```
### Env Vars Prefix
```sh
export APP_HOST=localhost;
export APP_PORT=8080;
```
```python
import cabina
env = cabina.Environment(prefix="APP_")
class Config(cabina.Config, cabina.Section):
API_HOST = env.str("HOST") # <- No "APP_" prefix
API_PORT = env.int("PORT")
assert Config.API_HOST == "localhost"
assert Config.API_PORT == 8080
```
### Inheritance
```python
import cabina
class Config(cabina.Config, cabina.Section):
DEBUG = False
class Api(cabina.Section):
API_HOST = "app.dev"
API_PORT = 5000
class ConfigLocal(Config):
DEBUG = True
class Api(Config.Api):
API_HOST = "localhost"
assert ConfigLocal.DEBUG is True
assert ConfigLocal.Api.API_HOST == "localhost"
assert ConfigLocal.Api.API_PORT == 5000
```