How to search text file line by line for '/##/'?

Im trying to search through text files line by line and if a line contains /##/ format, I want to print the line. I know the line I want will have this format because I'm trying to extract the date. Is there syntax for something like this? For example..

 if('/%d%d/' in line):
    print (line)

Is there something that I can use in between the two forward slashes that is equivalent to a digit 0-9? I have no problem searching the file line by line, here's my code:

items = os.listdir("C:/output3")
for names in items:
    if names.endswith(".txt"):
        with open('C:/output3/' + names) as currentFile:
            for i, line in enumerate(currentFile):
                line=line.rstrip()
                if('/%d%d/' in line):
                    print (line)
                else:
                    i = i + 1

Once I can extract the line I can use regex to search for digits in front/behind of the /'s. Thanks.