This function counts the number of whitespaces in a text.

$>>>$ count$\_$whitespaces$("\backslash$t $")$ # remember, a tab is $4$ white spaces

$6$

$>>>$ count$\_$whitespaces$("$ Hello World $")$

$3$

$>>>$ count$\_$whitespaces$("$#PythonRules"$)$

$0$

$>>>$ count$\_$whitespaces$("")$

$1$

$"""$