Extract variables from multiple NetCDF files stored in multiple folders

Question

I am trying to extract some variables from different netCDF files stored in different folders and save them in a CSV file.

Until now I'm trying to extract the needed variables from one file at a time, as follows:

    f1 = nc.Dataset('...')
    f2 = nc.Dataset('...')
    f3 = nc.Dataset('...')

and then:

lat1 = f1.variables['lat_l1b_echo_sar_ku'][:]  
lon1 = f1.variables['lon_l1b_echo_sar_ku'][:]
tim1 = f1.variables['time_l1b_echo_sar_ku'][:]
wav1 = f1.variables['i2q2_meas_ku_l1b_echo_sar_ku'][:]

Can anyone help me to batch this process?

Any help would be much appreciated.

Thanks