pymetkit#

Submodules#

Attributes#

MarsSelection

a mapping from MARS keys to user-supplied values.

Classes#

MarsRequest

A MARS request: a verb (e.g. retrieve) together with a

Functions#

parse_mars_request(→ list[MarsRequest])

Parse one or more MARS requests from a file-like object or a string.

Package Contents#

class MarsRequest(verb: str, selection: pymetkit.pymetkit_type.MarsSelection | None = None, /)#

A MARS request: a verb (e.g. retrieve) together with a MarsSelection describing the parameters and their values.

Parameters:

  • verb (str) – The request verb, e.g. retrieve.

  • selection (MarsSelection, optional) – Initial parameter values. Scalars are wrapped in a singleton list, collections are stringified, and /-separated strings are split.

Examples

>>> request = MarsRequest("retrieve", {"class": "od", "date": "20200101/20200102", "param": [151, 129]})
>>> request.verb()
'retrieve'
>>> request["class"]
'od'
>>> request["date"]
['20200101', '20200102']
>>> request["param"]
['151', '129']

Iterating yields (name, value) pairs:

>>> for key, value in request:
...     print(key, value)
class od
date ['20200101', '20200102']
param ['151', '129']
_verb#
selection: pymetkit.pymetkit_type.InternalMarsSelection#
_to_internal() → pymetkit._internal._MarsRequest#
classmethod _from_internal(internal: pymetkit._internal._MarsRequest) → MarsRequest#
verb() → str#

Return the request verb.

keys() → Iterator[str]#

Return an iterator over the parameter names in the request.

num_values(param: str) → int#

Return the number of values for a parameter.

expand(inherit: bool = True, strict: bool = False) → MarsRequest#

Return the expanded request.

Parameters:

  • inherit (bool) – If True, populate the expanded request with default values.

  • strict (bool) – If True, raise an error instead of a warning for invalid values.

Returns:

The request resulting from expansion.

Return type:

MarsRequest

validate() → None#

Check that the request is valid against the MARS language definition. Does not inherit missing parameters.

Raises:

MetKitException – If the request is incompatible with the MARS language definition.

merge(other: MarsRequest) → MarsRequest#

Merge the values of another request into this one and return the result as a new request. Does not modify either input. Both requests must contain the same parameters and the result must be compatible with the MARS language definition.

Parameters:

other (MarsRequest) – The request to merge with self.

Returns:

The result of the merge.

Return type:

MarsRequest

Raises:

  • ValueError – If the parameters in the two requests do not match.

  • MetKitException – If the resulting request is not compatible with the MARS language definition.

__iter__() → Iterator[tuple[str, str | list[str]]]#
__getitem__(param: str) → str | list[str]#
__setitem__(param: str, values) → None#
__contains__(param: str) → bool#
__eq__(other: object) → bool#
__hash__() → int#
__repr__() → str#
parse_mars_request(file_or_str: IO | str, strict: bool = False) → list[MarsRequest]#

Parse one or more MARS requests from a file-like object or a string.

Parameters:

  • file_or_str (str | IO) – A string or file-like object containing one or more MARS requests.

  • strict (bool) – Whether to raise an error (True) or a warning (False) when a request is not compatible with the MARS language definition. When False, the incompatible parameters are unset from the request.

Return type:

list[MarsRequest]

MarsSelection#

a mapping from MARS keys to user-supplied values.

Values may be a scalar (str, int, float) or a collection of those. A str containing / is treated as a MARS range/list expression and split on / by UserInputMapper.map_selection_to_internal().

Type:

Selection part of a MARS request