For this type of mad-lib program, I'm assuming youre asking how to concatenate two strings. In python you can do this by just doing
Code:
print("Concatenated strings: " + str1 + str2)
Python reads the addition operator (+) as a string concatenator when there's two strings around it.
However because I think you're going to need spaces around the words, you can do
Code:
print("Two strings with a space between them: " + str1, str2)
This will put a space between them so that it looks good in a sentence.