How to add whitespaces between two words in a string so that total string length has specific value

I am starting out with strings (creditcard numbers and validity status) such as:

'378282246310005 Invalid',
'30569309025904 Invalid',
'6011111111111117 valid'

and I would like to obtain final strings, where the total length is 40:

'378282246310005                  Invalid',
'30569309025904                   Invalid',
'6011111111111117                   valid'

Besides the Python string methods 'rjust', 'ljust' and 'center', are there any built-in string method to accomplish such a task, or would I need to write some function for it for example?

So far, I have tried:

string = '378282246310005 {} Invalid'
while len(string) < 40:
    string = string.format(' ')

Not sure how to progress from here.

Here's a manual solution using str.split and str.join:

L = ['378282246310005 Invalid',
     '30569309025904 Invalid',
     '6011111111111117 valid']

def formatter(x):
    x_split = x.split()
    n = sum(map(len, x_split))
    return (' '*(40-n)).join(x_split)

print(*map(formatter, L), sep='\n')

378282246310005                  Invalid
30569309025904                   Invalid
6011111111111117                   valid

This works even if your input string contains multiple whitespace.