eccodes

import eccodes import os # --- Quickstart setup: Ensure a GRIB file exists for demonstration --- # In a real scenario, you would point to your actual GRIB file. grib_filepath = "quickstart_sample.grib" if not os.path.exists(grib_filepath): print(f"Creating a dummy GRIB file '{grib_filepath}' for quickstart.") try: # Create a basic GRIB message from a sample. # This requires the eccodes sample data to be accessible. # If ECCODES_SAMPLES_PATH is not set, this might fail. gid = eccodes.codes_grib_new_from_samples("GRIB2") eccodes.codes_set(gid, "discipline", 0) # Meteorology eccodes.codes_set(gid, "parameterCategory", 0) # Temperature eccodes.codes_set(gid, "parameterNumber", 0) # Temperature (K) eccodes.codes_set_array(gid, "values", [273.15, 274.15, 275.15]) # Dummy data with open(grib_filepath, 'wb') as f: eccodes.codes_write(gid, f) eccodes.codes_release(gid) print(f"Successfully created a basic GRIB file: {grib_filepath}") except eccodes.CodesInternalError as e: print(f"Warning: Could not create a valid GRIB sample using eccodes ({e}).") print("Falling back to an empty dummy file. Quickstart may not show full functionality.") with open(grib_filepath, 'w') as f: f.write("DUMMY_FILE_CONTENT_NOT_GRIB") except Exception as e: print(f"An unexpected error occurred during GRIB sample creation: {e}") with open(grib_filepath, 'w') as f: f.write("DUMMY_FILE_CONTENT_NOT_GRIB") # --- End of Quickstart setup --- # Main Quickstart logic: Reading GRIB messages try: message_count = 0 with eccodes.GribFile(grib_filepath) as gf: print(f"\nOpened GRIB file: {grib_filepath}") for i, msg in enumerate(gf): message_count += 1 print(f" Processing Message {i+1}:") try: # Access common keys using the high-level interface centre = msg.get("centre", "N/A") param = msg.get("shortName", "N/A") level = msg.get("level", "N/A") date = msg.get("date", "N/A") time = msg.get("time", "N/A") print(f" Centre: {centre}, Parameter: {param}, Level: {level}, Date: {date}, Time: {time}") # Access values (can be a large array). Avoid printing all. values = msg.get("values", []) if values: print(f" First 5 values: {values[:min(5, len(values))]}") else: print(" No values found or dummy file used.") except eccodes.KeyError as e: print(f" Warning: Key not found in message: {e}") except Exception as e: print(f" An error occurred while processing message: {e}") if message_count >= 1: # Process only the first message for brevity break if message_count == 0: print(f"No GRIB messages found in {grib_filepath}. (Might be a dummy file or empty).") except eccodes.WrongElementException as e: print(f"\nError: '{grib_filepath}' is not a valid GRIB file or corrupted. Details: {e}") except FileNotFoundError: print(f"\nError: GRIB file '{grib_filepath}' not found.") except Exception as e: print(f"\nAn unexpected error occurred during GRIB file processing: {e}") finally: # Clean up the dummy file if os.path.exists(grib_filepath) and grib_filepath == "quickstart_sample.grib": os.remove(grib_filepath) print(f"Cleaned up dummy file: {grib_filepath}")