stringbuilder

I have been trying to build a Python application that can generate a text file consisting of multiple lines of text, and I was wondering if there is any way to do this without having to create a new string object every time I want to add a line of text to the file. I stumbled upon the Python String class, and someone suggested on a forum post that I should use the StringBuilder class from C# to make my code more efficient.
However, I am not quite sure how to use the StringBuilder class in Python or if there is an equivalent class that I can use. I have tried using the io package to create a file and adding text to it, but it seems to be very slow when it comes to adding many lines of text. For example, when I tried to add 100,000 lines of text to the file, it took almost a minute to complete.
Is there a more efficient way to generate a large text file in Python? Can I use the StringBuilder class from C# in Python somehow, or is there another built-in class that I can use to make writing to a file more efficient? Any help or suggestions would be greatly appreciated.