Python API Guide

Importing nc_check registers a dataset accessor at ds.check.

import xarray as xr
import nc_check

Main Methods

ds.check.compliance(...)

Run convention checks (cf, ferret, or both).

Common options:

• conventions: "cf,ferret" (default), "cf", or "ferret"
• engine: "auto" (default), "cfchecker", "heuristic"
• fallback_to_heuristic: True by default
• domain: optional standard-name suggestion domain (ocean, atmosphere, land, cryosphere, biogeochemistry)
• report_format: auto, python, tables, html
• report_html_file: path, only valid with report_format="html"

Returns:

• dict for python
• str for html
• None for tables

ds.check.make_cf_compliant()

Returns a copied dataset with safe metadata fixes. The original dataset is unchanged.

Key updates:

• sets Conventions = "CF-1.12"
• normalizes key CF attribute names to expected lowercase forms
• fills inferred axis coordinate metadata
• creates missing inferred axis coordinates when needed
• sets extent attrs when possible:
• time_coverage_start
• time_coverage_end
• geospatial_lat_min
• geospatial_lat_max
• geospatial_lon_min
• geospatial_lon_max
• removes coordinate _FillValue from attrs/encoding

ds.check.ocean_cover(...)

Ocean-grid sanity checks for one variable or all eligible variables.

Common options:

• var_name: optional variable name
• lon_name, lat_name: optional coordinate names (auto-inferred if omitted)
• time_name: preferred time dim name (default time)
• check_edge_of_map: detect persistent missing longitude bands
• check_land_ocean_offset: reference-point land/ocean alignment test
• report_format, report_html_file

ds.check.time_cover(...)

Time slice missing-data coverage checks.

Common options:

• var_name: optional variable name
• time_name: preferred time dim name (default time)
• report_format, report_html_file

ds.check.all(...)

Runs selected checks and returns one combined report.

Check toggles:

• compliance=True
• ocean_cover=True
• time_cover=True

Forwards method-specific options to each check family and produces:

• check_summary
• per-check reports
• overall status fields (overall_status, overall_ok)