Download_data_CFSR.py 文件源码

def Download_data(Date, Version, output_folder, Var):        
    """
    This function downloads CFSR data from the FTP server
                For - CFSR:    ftp://nomads.ncdc.noaa.gov/CFSR/HP_time_series/
                    - CFSRv2:  http://nomads.ncdc.noaa.gov/modeldata/cfsv2_analysis_timeseries/

    Keyword arguments:
    Date -- pandas timestamp day
    Version -- 1 or 2 (1 = CFSR, 2 = CFSRv2)            
    output_folder -- The directory for storing the downloaded files
    Var -- The variable that must be downloaded from the server ('dlwsfc','uswsfc','dswsfc','ulwsfc')
    """
    # Define the filename that must be downloaded     
    if Version == 1:
        filename = Var + '.gdas.' + str(Date.strftime('%Y')) + str(Date.strftime('%m')) + '.grb2'
    if Version == 2:
        filename = Var + '.gdas.' + str(Date.strftime('%Y')) + str(Date.strftime('%m')) + '.grib2'

    try:
         # download the file when it not exist                  
        local_filename = os.path.join(output_folder, filename)
        if not os.path.exists(local_filename):
            Downloaded = 0
            Times = 0
            while Downloaded == 0:              
                # Create the command and run the command in cmd
                if Version == 1:
                    FTP_name = 'ftp://nomads.ncdc.noaa.gov/CFSR/HP_time_series/' + Date.strftime('%Y') + Date.strftime('%m')+ '/' + filename

                if Version == 2:
                    FTP_name = 'https://nomads.ncdc.noaa.gov/modeldata/cfsv2_analysis_timeseries/' + Date.strftime('%Y') + '/' + Date.strftime('%Y') + Date.strftime('%m')+ '/' + filename

                curl = pycurl.Curl()
                curl.setopt(pycurl.URL, FTP_name)
                fp = open(local_filename, "wb")
                curl.setopt(pycurl.SSL_VERIFYPEER, 0)
                curl.setopt(pycurl.SSL_VERIFYHOST, 0)
                curl.setopt(pycurl.WRITEDATA, fp)
                curl.perform()
                curl.close()
                fp.close()  
                statinfo = os.stat(local_filename)      
                if int(statinfo.st_size) > 10000:
                    Downloaded = 1  
                else:
                    Times += 1
                    if Times == 10:
                        Downloaded = 1
    except:
        print 'Was not able to download the CFSR file from the FTP server'

    return(local_filename)