In Python,sometimes I see the string variable using ' ' to define it; sometimes I see the string variable using " " to define it.
For instance, it seems to me that both of the followings work
file_to_read = os.path.join(path, 'file.txt')
file_to_read = os.path.join(path, "file.txt")
My question is that are ' 'and " " totally interchangeble?