Files
feelGrib/downloader.py
laurent.deleers@gmail.com 9b5fcd0100 adapt mecator
update interface
adapt time base before converting to grib
refactor some stuff
remove debug comments
2025-05-21 19:13:46 +00:00

108 lines
4.0 KiB
Python

import os
from datetime import datetime, timedelta
from copernicusmarine import subset
import subprocess
class CopernicusDownloader:
def __init__(self, username="", password=""):
self.dataset_id = "cmems_mod_ibi_phy_anfc_0.027deg-2D_PT1H-m"
self.username = username
self.password = password
self.output_file = os.path.join(os.getcwd(), "downloads", "download.nc")
self.prepared_file = os.path.join(os.getcwd(), "downloads", "download_prepared.nc")
self.output_grib = os.path.join(os.getcwd(), "downloads", "download.grib2")
self.lat_min = 0.0
self.lat_max = 0.0
self.lon_min = 0.0
self.lon_max = 0.0
self.days = 1
def retrieve_grib2(self, lat_min, lat_max, lon_min, lon_max, days):
self.lat_min = lat_min
self.lat_max = lat_max
self.lon_min = lon_min
self.lon_max = lon_max
self.days = days
# print(f"Démarage du téléchargement avec {lat_min} - {lat_max} - {lon_min} - {lon_max} - {days} ")
self.download(self.output_file)
self.apply_setreftime(self.output_file,self.prepared_file)
self.convert_to_grib2(self.prepared_file,self.output_grib)
return self.output_grib
def download(self,outfile):
today = datetime.utcnow()
start_date = today.strftime("%Y-%m-%dT00:00:00")
end_date = (today + timedelta(days=self.days)).strftime("%Y-%m-%dT23:00:00")
save_dir = os.path.join(os.getcwd(), "downloads")
os.makedirs(save_dir, exist_ok=True)
subset(
dataset_id=self.dataset_id,
output_filename=outfile,
variables=["uo", "vo"], # removed "thetao" (temperature) and "zos" (elevation)
minimum_longitude=self.lon_min,
maximum_longitude=self.lon_max,
minimum_latitude=self.lat_min,
maximum_latitude=self.lat_max,
start_datetime=start_date,
end_datetime=end_date,
username=self.username,
password=self.password
)
print(f"✅ File downloaded to : {outfile}")
def extract_date_and_time(self,infile):
# Extract the first timecode of the nc file
try:
result = subprocess.run(
["cdo", "showtimestamp", infile],
check=True,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE,
text=True
)
# Récupérer le premier timestamp : ex. 2025-05-21T00:00:00
first_timestamp = result.stdout.strip().split()[0]
date, time = first_timestamp.split('T')
return date, time
except subprocess.CalledProcessError as e:
print(f"[CDO Error] {e.stderr}")
except Exception as e:
print(f"[Error] {e}")
return None, None
def apply_setreftime(self,infile,outfile):
# Apply the command cdo -setreftime,<date>,<heure> <input> <output> to define a reference time
date, time = self.extract_date_and_time(infile)
if not date or not time:
print("Cannot retrieve date/time from this file.")
return
try:
subprocess.run(
["cdo", f"-setreftime,{date},{time}", infile, outfile],
check=True
)
print(f"✅ File adapted with correct time ref {date} - {time} : {outfile}")
except subprocess.CalledProcessError as e:
print(f"[Error when setting reference time with CDO -setreftime] {e.stderr}")
def convert_to_grib2(self,infile,outfile):
if not os.path.exists(infile):
raise FileNotFoundError(f"File not found : {infile}")
try:
subprocess.run(["cdo", "-f", "grb2", "copy", infile, outfile], check=True)
print(f"✅ File converted to grib : {outfile}")
return outfile
except subprocess.CalledProcessError as e:
raise RuntimeError(f"Error when converting with CDO : {e}")