pybind11 bindings#

pymetkit_bindings is the compiled pybind11 extension module that binds the metkit C++ classes directly. It is the lowest layer of PyMetKit and is consumed by pymetkit._internal; the raw MarsRequest class it exposes is re-exported there as _MarsRequest.

Warning

This is an internal, low-level layer. Application code should use the Pythonic API (pymetkit.pymetkit.MarsRequest, pymetkit.pymetkit_type.MarsSelection and pymetkit.pymetkit.parse_mars_request()) rather than these bindings directly. The signatures below map one-to-one onto metkit::mars::MarsRequest and are not covered by the same value-normalization or error-translation guarantees.

The extension is built from src/pymetkit_bindings/bindings.cc and staged into the wheel as its own top-level package. The shared library libmetkit and its dependencies must be loaded (via findlibs) before the module is imported, and init_bindings() must be called once before any other call — both are handled automatically by pymetkit._internal.

Module-level functions#

init_bindings()#

Initialise the eckit runtime (eckit::Main). Must be called once, before any other binding call, when metkit is loaded as a shared library from Python.

version_info()#

Return a list of (name, version, git_sha1, path) tuples describing every eckit-registered library currently loaded (e.g. eckit, eccodes, metkit). Used by the python -m pymetkit diagnostics CLI.

Return type:

list[tuple[str, str, str, str]]

parse_marsrequest(string, strict)#

Parse a single MARS request from string.

Parameters:

  • string (str) – the MARS request text.

  • strict (bool) – raise an error (rather than a warning) on invalid values.

Returns:

the parsed request.

Return type:

MarsRequest

parse_marsrequests(string, strict)#

Parse one or more MARS requests from string.

Parameters:

  • string (str) – text containing one or more MARS requests.

  • strict (bool) – raise an error (rather than a warning) on invalid values.

Returns:

the parsed requests.

Return type:

list[MarsRequest]

Classes#

class MarsRequest#

A thin binding of metkit::mars::MarsRequest. Values are passed and returned as lists of strings; no normalization is performed at this layer.

__init__()#
__init__(verb)

Construct an empty request, or a request with the given verb.

Parameters:

verb (str) – the request verb (e.g. "retrieve").

verb()#

Return the request verb.

Return type:

str

set_verb(verb)#

Set the request verb.

Parameters:

verb (str) – the verb to set.

set(param, values)#

Set the values of a parameter.

Parameters:

  • param (str) – the parameter name.

  • values (list[str]) – the parameter values.

has(param)#

Return whether param is present in the request.

Parameters:

param (str) – the parameter name.

Return type:

bool

params()#

Return the parameter names present in the request.

Return type:

list[str]

count_values(param)#

Return the number of values held for param.

Parameters:

param (str) – the parameter name.

Return type:

int

values(param)#

Return the values held for param.

Parameters:

param (str) – the parameter name.

Return type:

list[str]

merge(other)#

Merge other into this request in place: for each shared parameter, the values of other that are not already present are appended (order-preserving union).

Parameters:

other (MarsRequest) – the request to merge in.

expand(inherit, strict)#

Return the request expanded against the MARS language definition, using metkit::mars::MarsExpansion.

Parameters:

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

  • strict (bool) – raise an error (rather than a warning) on invalid values.

Returns:

the expanded request.

Return type:

MarsRequest

__repr__()#

Return the request rendered as a MARS request string (asString()).

Return type:

str