CanCat | swiss army knife of Controller Area Networks

Hello I wanted cancat Two dataframe which share same column name and save as indivisual file having same column name and save file as column name

my dataframe looking like

I'm trying to concatenate 3 videos at time from a list.txt, i can concatenate all the videos in the list in a single long video, but i wish to concatenate x videos from the list in a single output, then concatenate the next x videos from the same list in another single output and so on.

The script i'm developing it's written in python, it fetches some videos from a server and save them locally in a folder and write my concat.txt, then ffmpeg read the concat.txt and create a single output.mp4

I am trying to record a video from a canvas with a series of pictures, gif, and also some videos even songs(audio) displaying through time.
Now I have achieved:
- record a video with pictures, gif and videos without any audio using canvas.captureStream() and MediaRecorder
What I want to know:
- Figure out why the recorded video has no audio of the video inside the canvas?
- Is there a way to cancat songs into the recorded video at a specific timestamp?

I notice a similar question (link below) about how to record canvas and audio simultaneously, but I have no idea why the video's audio should deal separately. If it is the only solution, is there any way to add the audio track at a specific time instead of the beginning of the recorded video?

MediaStream Capture Canvas and Audio Simultaneously

Thanks!

I have two tables with the same number of rows but not one column I could join them toghether. Like:

Using following code I want to take two strings, concat them and display them on same line using sys.stdin.readline() for input and sys.stdout.write() for output.