Converting integers in a list to list of digits

I was solving a problem with input:

[[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]

Desired output:

[1,11,121,1331,14641]

So is there any way to convert my array to the desired output using python3

My code:

numRows=5
li=list([str(11**i )for i in range(numRows)])
li=[int("".join(i))for i in li]

I tried several ways but was not able to reach the desired output

Why convert to/from strings when this can be done arithmetically?

lol = [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]
output = []
for e in lol:
    n = 0
    for v in e:
        n = n * 10 + v
    output.append(n)
print(output)

Output:

[1, 11, 121, 1331, 14641]

input_array = [[1],[1,1],[1,2,1],[1,3,3,1],[1,4,6,4,1]]

output_array = []

for row in input_array:
    row_output = [str(num) for num in row]
    row_output = ''.join(row_output)
    row_output = int(row_output)
    output_array.append(row_output)

print(output_array)

Regarding your second attempted method, it is very close to working. The str.join method only works on lists of strings, but you are attempting to use it on a list of integers.

This can be fixed by simply converting the list to all strings:

li=[int("".join(map(str, i))) for i in li]

Here is a math based solution, without relying on int to str conversion.
Of course, you can use list comprehension, but I've just kept it simple.

def concat_list_digits(ldigits):
    for i, item in enumerate(ldigits):
        curr_len = len(item)
        value = 0
        for i in range(curr_len):
            value += item[i] * (10 ** (curr_len - i - 1))

        ldigits[i] = value
    return ldigits


if __name__ == "__main__":
    digits = [[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]
    print(concat_list_digits(digits))