Converting number words into numbers - Python

Question

I'm trying to make a program that takes a string of number words "One hundred ninety two thousand seven hundred thirty one" and turn it into the corresponding number. This is the code I have so far:

def string_to_num(text):
    text = text.lower()
    words = text.split()
    numbers = []
    output1 = []
    output2 = []
    output3 = []
    output4 = []
    hold = 1
    l = 1
    for current_word in words:
        number  = word_to_number(current_word)
        numbers.append(number)
    for i in range(len(numbers)):
        current_num = numbers[i]
        if i == len(numbers)-1:
            output1.append(current_num)
            continue
        else:
            previous_num = numbers[i-1]
            if current_num > 999:
                output1.append(current_num)
                continue
            else:
                if previous_num < current_num:
                    output1.append(current_num * previous_num)
                    output1.pop(i-l)
                    l += 1
                    continue
                else:
                    output1.append(current_num)
                    continue
    for i in range(1, len(output1[:])):
        current_num = output1[i]
        previous_num = output1[i-1]
        if current_num > 999:
            output2.append(current_num)
            continue
        else:
            if output1[i-1] > current_num and previous_num < 1000:
                output2.append(current_num + previous_num)
                continue
            else:
                output2.append(current_num)

print('output2', output2)
string_to_num('One hundred ninety two thousand seven hundred thirty one')

It works in the way that at the beginning, the function takes the number word and puts it through another function I have 'word_to_number()' that converts it to its corresponding number. I put all the values of numbers into a loop that gives the following result:

[1, 100, 90, 2, 1000, 7, 100, 30, 1]

The next part of the program adds makes sure the hundreds are added multiplied by the right factor. It takes the previous list and converts it into a list that looks like this:

[100, 90, 2, 1000, 700, 30, 1]

Note that the 100 and 700 are now combined.

The part that Im having trouble with is adding the numbers together and adding them to a new list, output2. The current code above produces the following list:

[190, 92, 1000, 700, 730, 31]

When it should look like this:

[192, 1000, 731]

Any Idea on how to get this working correctly? I've tried adding the numbers together and then using .pop to remove the original number from the new list, but I get the error 'Index is not in range'. Any help is greatly appreciated!