从PHP索引调用python脚本超出范围

I'm calling a python script from my PHP code, I need to pass 7 variable: a few strings, a couple of array and a matrix.

I tried to use both Shell_Exec and exec(), but I get always the same problem:

matrixdata = sys.argv[7]
IndexError: list index out of range

The first thought was " I passed the wrong number of variable ", but checking they are 7. This is my python code:

 listlabel = str(sys.argv[2])
 listdata = (sys.argv[1])
 typechart = str(sys.argv[3])
 name = str(sys.argv[4])
 typedata = str(sys.argv[5])
 title = str(sys.argv[6])
 matrixdata = sys.argv[7] //this is the matrix

This is my PHP Lines to call it

//json encoding for the array:
$total = json_encode(compact($listlabel));
$event = json_encode(compact($listdata));
$event = json_encode(compact($matrixdata));


exec("python ../home/path../create_chart.py $total $event $chart $name $typedata $title $matrixdata", $output);
//all the parameters exist and the path is correct

I'm passing 7 arguments, I'm getting 7 arguments. I don't understand where the problem is.

Before to added the last matrix, this line was working with 7 elements, instead of 7, I also tried with 8 elements and 9 instead of 7, but no luck.

Let me know if someone can help me, thank you.