Implement a function to calculate the sum of the numerical values in a nested list. For example :

```python
sum_nested([1, [2, [3, [4]]]]) -> 10
```

Difficulty: introductory

Starter code:

def sum_nested(lst):
	

Solutions:
def sum_nested(lst):
    return sum(sum_nested(x) if isinstance(x,list) else x for x in lst)

def sum_nested(lst):
    total = 0
    for ele in lst:
        total += ele if type(ele) != list else sum_nested(ele)
        
    return total

import re

def sum_nested(lst):
    return sum(map(int, re.findall('\d+', str(lst))))


def sum_nested(lst):
    return sum(map(sum_nested, lst)) if isinstance(lst, list) else lst 

import re

def sum_nested(lst):
    return sum(int(x) for x in re.findall('\d+', str(lst)))

def sum_nested(lst):
    if not isinstance(lst, list):
        return lst

    return sum(sum_nested(x) for x in lst)

def sum_nested(lst):
    s = 0
    for l in lst:
        if type(l) == list:
            s += sum_nested(l)
        else:
            s += l
    return s

def sum_nested(L):
    if L == []:
        return 0
    if type(L[0]) == int:
        if len(L) == 1:
            return L[0]
        else:
            return L[0]+sum_nested(L[1:])
    else:
        return sum_nested(L[0])+sum_nested(L[1:])
    
    #the sum of every numerical value in the list and its sublists


def sum_nested(L):
    return sum(x if isinstance(x, int) else sum_nested(x) for x in L)

def sum_nested(lst):
    return sum(sum_nested(e) if type(e) is list else e for e in lst)