title: Accessing data range with h5py
body: <p>I have an h5 file that contains 62 different attributes. I would like to access the data range of each one of them.</p>
  
  <p>to explain more here what I'm doing </p>
  
  <pre><code>import h5py 
  the_file =  h5py.File("myfile.h5","r")
  data = the_file["data"]
  att = data.keys()
  </code></pre>
  
  <p>the previous code gives me a list of attributes "U","T","H",.....etc</p>
  
  <p>lets say I want to know what is the minimum and maximum value of "U". how can I do that ?</p>
  
  <p>this is the output of running "h5dump -H"</p>
  
  <pre><code>HDF5 "myfile.h5" {
  GROUP "/" {
     GROUP "data" {
        ATTRIBUTE "datafield_names" {
           DATATYPE  H5T_STRING {
                 STRSIZE 8;
                 STRPAD H5T_STR_SPACEPAD;
                 CSET H5T_CSET_ASCII;
                 CTYPE H5T_C_S1;
              }
           DATASPACE  SIMPLE { ( 62 ) / ( 62 ) }
        }
        ATTRIBUTE "dimensions" {
           DATATYPE  H5T_STD_I32BE
           DATASPACE  SIMPLE { ( 4 ) / ( 4 ) }
        }
        ATTRIBUTE "time_variables" {
           DATATYPE  H5T_IEEE_F64BE
           DATASPACE  SIMPLE { ( 2 ) / ( 2 ) }
        }
        DATASET "Temperature" {
           DATATYPE  H5T_IEEE_F64BE
           DATASPACE  SIMPLE { ( 256, 512, 1024 ) / ( 256, 512, 1024 ) }
        }
  </code></pre>