Sorry for all the backslashed double-quotes:

>perl -wMstrict -le
"my @data = (
   { \"name\" => \"joe\",
     \"age\" => 21,
     \"weight\" => 150,
     \"height\" => \"\",
     \"sex\" => \"\",
     },
   { \"name\" => \"joe\",
     \"age\" => \"\",
     \"weight\" => \"\",
     \"height\" => \"6'0\",
     \"sex\" => \"\",
     },
   { \"name\" => \"joe\",
      \"age\" => \"21\",
      \"weight\" => \"\",
      \"height\" => \"\",
      \"sex\" => \"male\",
      },
   );
 my %hash =
   map {
     my $hr = $_;
     map  { $_, $hr->{$_} }
     grep $hr->{$_} ne '',
     keys %$hr
     }
   @data
   ;
 use Data::Dumper;
 print Dumper \%hash;
"
$VAR1 = {
          'name' => 'joe',
          'weight' => 150,
          'sex' => 'male',
          'height' => '6\'0',
          'age' => '21'
        };
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