env_var

class env_var.env(var_name: str)

Utility to validate and type cast environment variables. All methods return an instance of the _env class.

as_bool()

Parses env var as a boolen

as_date()

Parses env var using dateutil.parser.parse()

as_email()

Makes sure env var is a valid email string

as_enum(enum: Type[env_var.env.EnumType]) → env_var.env._env[env_var.env.EnumType]

Parses env var as an Enum

as_float(min: Optional[float] = None, max: Optional[float] = None)

Parses env var as a float

Parameters

  • min – min acceptable value

  • max – max acceptable value

as_float_list(split_on: str = ',', min_item_value: Optional[float] = None, max_item_value: Optional[float] = None)

Parses env var as a list of floats

Parameters

  • split_on – string on which env var should be split

  • base – the base defaults to 10; valid bases are 0 and 2-36

  • min_item_value – min acceptable value for a single list item

  • max_item_value – max acceptable value for a single list item

as_float_negative()

Parses env var as a negative float

as_float_positive()

Parses env var as a positive float (0 included)

as_hostname()

Makes sure env var is a valid hostname string

as_int(base: Optional[int] = 10, min: Optional[int] = None, max: Optional[int] = None)

Parses env var as an int

Parameters

  • base – the base defaults to 10; valid bases are 0 and 2-36

  • min – min acceptable value

  • max – max acceptable value

as_int_list(split_on: str = ',', base: Optional[int] = 10, min_item_value: Optional[int] = None, max_item_value: Optional[int] = None)

Parses env var as a list of ints

Parameters

  • split_on – string on which env var should be split

  • base – the base defaults to 10; valid bases are 0 and 2-36

  • min_item_value – min acceptable value for a single list item

  • max_item_value – max acceptable value for a single list item

as_int_negative(base: Optional[int] = None)

Parses env var as a negative int

Parameters

base – the base defaults to 10; valid bases are 0 and 2-36

as_int_positive(base: Optional[int] = None)

Parses env var as a positive int (0 included)

Parameters

base – the base defaults to 10; valid bases are 0 and 2-36

as_ip_address()

Parses env var using ipaddress.ip_address()

as_ip_interface()

Parses env var using ipaddress.ip_interface()

as_ip_network()

Parses env var using ipaddress.ip_network()

as_iso_date()

Parses env var using dateutil.parser.isoparse()

as_iso_date_string()

Makes sure env var is as a valid rfc3339 string

as_iso_duration()

Parses env var using isoduration.parse_duration()

as_list(item_transformer: Callable[[str], env_var.env.T], split_on: str = ',') → env_var.env._env[List[env_var.env.T]]

Parses env var as a list

Parameters

  • item_transformer – function called with every value of the split string

  • split_on – string on which env var should be split

as_port_number()

Parses env var as a port number (int between 1-65535)

as_string()

Literally does nothing with the env var

as_string_list(split_on: str = ',')

Parses env var as a list of strings

Parameters

split_on – string on which env var should be split

as_uri()

Makes sure env var is a valid uri string

as_url()

Makes sure env var is a valid url string

as_urlparse()

Parses env var using urllib.parse.urlparse()

as_uuid()

Makes sure env var is a valid uuid string

custom_transformer(transformer: Callable[[str], env_var.env.T]) → env_var.env._env[env_var.env.T]

Parse/validate env var using custom transformer

should_match(pattern: Union[Pattern[str], str])

Makes sure env var is matching given pattern

class env_var.env._env(_env__var_name: str, _env__transformer: Callable[[str], env_var.env.T], _env__default: Optional[env_var.env.T] = None)

Helper generic class that is actually returned by all methods of the env class. It’s not supposed to be instantiated directly by the user of the library.

default(val: env_var.env.T)

Sets the default value to return in case the environment variable is not defined. Note, this value will be returned as is, without any validation the value from the environment variable might go through.

Parameters

val – default value to use

Returns

self

optional() → Optional[env_var.env.T]
Returns

the parsed environment variable, if it’s set; if not, the default value if it was defined or None

Raises

EnvVarValidationError –

required() → env_var.env.T
Returns

the parsed environment variable

Raises
exception env_var.errors.EnvVarNotDefinedError(var_name: str)

Exception raised when env var is not set

exception env_var.errors.EnvVarValidationError(var_name: str, *args)

Exception raised when env var is not valid