In [45]: nc = netCDF4.Dataset('GPCP/dat/gpcp_v01r03_monthly_199610-201812.nc','r')

# Summaries
In [46]: nc
Out[46]:
<class 'netCDF4._netCDF4.Dataset'>
root group (NETCDF3_CLASSIC data model, file format NETCDF3):
    history: 2019-04-10T10:40:23UTC, Akira Takeshima, The University of Tokyo, Created this file.
    dimensions(sizes): time(267), latitude(180), longitude(360)
    variables(dimensions): float32 time(time), float64 month(time), float64 year(time), float32 latitude(latitude), float32 longitude(longitude), float64 precip(time,latitude,longitude)
    groups:

# Details
In [47]: nc.variables
Out[47]:
OrderedDict([('time', <class 'netCDF4._netCDF4.Variable'>
              float32 time(time)
                  units: months since 1996-10-01
              unlimited dimensions:
              current shape = (267,)
              filling on, default _FillValue of 9.969209968386869e+36 used),
             ('month', <class 'netCDF4._netCDF4.Variable'>
              float64 month(time)
                  units: month
              unlimited dimensions:
              current shape = (267,)
              filling on, default _FillValue of 9.969209968386869e+36 used),
             ('year', <class 'netCDF4._netCDF4.Variable'>
              float64 year(time)
                  units: year
              unlimited dimensions:
              current shape = (267,)
              filling on, default _FillValue of 9.969209968386869e+36 used),
             ('latitude', <class 'netCDF4._netCDF4.Variable'>
              float32 latitude(latitude)
              unlimited dimensions:
              current shape = (180,)
              filling on, default _FillValue of 9.969209968386869e+36 used),
             ('longitude', <class 'netCDF4._netCDF4.Variable'>
              float32 longitude(longitude)
              unlimited dimensions:
              current shape = (360,)
              filling on, default _FillValue of 9.969209968386869e+36 used),
             ('precip', <class 'netCDF4._netCDF4.Variable'>
              float64 precip(time, latitude, longitude)
                  units: mm/month
              unlimited dimensions:
              current shape = (267, 180, 360)
              filling on, default _FillValue of 9.969209968386869e+36 used)])

# Names
In [48]: nc.variables.keys()
Out[48]: odict_keys(['time', 'month', 'year', 'latitude', 'longitude', 'precip'])