Improve conditions and refactor dataset classes (#475)

* Reimplement conditions

* Refactor datasets and implement LabelBatch

---------

Co-authored-by: Dario Coscia <dariocos99@gmail.com>

code_formatter.sh

@@ -2,51 +2,19 @@
 
 #######################################
 
-required_command="yapf unexpand"
-code_directories="pina tests"
+required_command="black"
+code_directories=("pina" "tests")
 
 #######################################
 
-usage() {
-	echo
-	echo -e "\tUsage: $0 [files]"
-	echo
-	echo -e "\tIf not files are specified, script formats all ".py" files"
-	echo -e "\tin code directories ($code_directories); otherwise, formats"
-	echo -e "\tall given files"
-	echo
-	echo -e "\tRequired command: $required_command"
-	echo
-	exit 0
-}
-
-
-[[ $1 == "-h" ]] && usage
-
 # Test for required program
-for comm in $required_command; do
-	command -v $comm >/dev/null 2>&1 || {
-		echo "I require $comm but it's not installed. Aborting." >&2; 
-		exit 1
-	}
-done
+if ! command -v $required_command >/dev/null 2>&1; then
+    echo "I require $required_command but it's not installed. Install dev dependencies."
+    echo "Aborting." >&2
+    exit 1
+fi
 
-# Find all python files in code directories
-python_files=""
-for dir in $code_directories; do
-    python_files="$python_files $(find $dir -name '*.py')"
-done
-[[ $# != 0 ]] && python_files=$@
-
-
-# Here the important part: yapf format the files.
-for file in $python_files; do
-	echo "Making beatiful $file..."
-	[[ ! -f $file ]] && echo "$file does not exist; $0 -h for more info" && exit
-	
-	yapf --style='{
-					based_on_style: pep8, 
-				   	indent_width: 4,
-					column_limit: 80
-			  	  }' -i $file
-done
+# Run black formatter
+for dir in "${code_directories[@]}"; do
+    python -m black --line-length 80 "$dir"
+done