arlmet.File

class arlmet.File(path, mode='r', *, source=None, grid=None, vertical_axis=None)

Read or write an ARL meteorology file.

Parameters:

• path (path-like) – Location of the ARL file on disk.

• mode ({"r", "w"}, default "r") – File mode. Read mode scans the file immediately; write mode expects the caller to provide source, grid, and vertical_axis before creating records.

• source (str, optional) – Four-character ARL source identifier used when writing.

• grid (Grid, optional) – Horizontal grid metadata used when writing.

• vertical_axis (VerticalAxis, optional) – Vertical axis metadata used when writing.

path

Filesystem path for the ARL file.

Type:

pathlib.Path

mode

Active file mode.

Type:

{“r”, “w”}

times

Sorted valid times discovered in the file.

Type:

list[pandas.Timestamp]

source

ARL source identifier.

Type:

str

grid

Horizontal grid metadata.

Type:

Grid

vertical_axis

Vertical coordinate metadata.

Type:

VerticalAxis

variables

Lazy accessor for variable-wise views inherited from RecordCollection.

Type:

VariableAccessor

__getitem__(key)

Get a RecordSet by valid time (Timestamp or string), or by position in times (int).

__iter__()

Iterate over valid times in times order (sorted).

create_grid(...)

Build and attach a Grid when writing a new file.

create_recordset(time, \*, forecast=None)

Create a writable RecordSet for one valid time.

add_record(time, variable, level, \*, forecast, data=None, diff=None)

Add one writable DataRecord, creating its RecordSet if needed.

flush()

Write pending record sets to disk and release their in-memory data.

sample_points(points, variables, ...)

Interpolate fields at arbitrary lon/lat/z sample points.

extract_subset(dest, ...)

Write a spatial/vertical subset to a new ARL file and return its path.

to_dataset(...)

Project the file into the simplified analysis xarray Dataset.

close()

Flush pending writes and release the file handle.

Examples

>>> import arlmet
>>> with arlmet.File("met.arl") as met:
...     met.times[0]
Timestamp('2024-07-18 00:00:00')

Methods

File.__init__(path[, mode, source, grid, ...])
File.add_record(time, variable, level, *, ...)	Add one writable DataRecord, creating its RecordSet if needed.
File.close()	Flush pending writes and close the managed binary file handle.
File.create_grid(nx, ny, *, pole_lat, ...)	Create and attach the horizontal grid metadata for a writable file.
File.create_recordset(time, *[, forecast])	Create a writable RecordSet for one valid time.
File.extract_subset(dest, *[, bbox, levels, ...])	Write a spatial/vertical subset of this file to a new ARL file.
File.flush()	Write pending record sets to disk and release their in-memory data.
File.sample_points(points, variables, *[, ...])	Sample fields from this file at arbitrary lon/lat/z points.
File.to_dataset(*[, drop_variables, bbox, ...])	Project this file into the simplified analysis Dataset representation.

Attributes

File.grid
File.handle
File.record_length
File.records	All DataRecords in the file, in times order.
File.size
File.source
File.times	Return a sorted list of timestamps in the file.
File.vertical_axis