I2C with Numeric Display

[psyko]

How can i do something like that https://www.youtube.com/watch?v=n-QBOEkK3hI in Python?
I already know how to connect a Port Expander to the raspi but how can i get letters on the Display?

[Grumpy Mike]

You need to connect each of the segments in the 7 segment display as if they were LEDs with their own current limiting resistor. Then it is a matter of making the patterns correspond the the numbers you want.
This link shows you how to do it in C but Python is very similar. Just use a list to store the bit patterns.
http://www.thebox.myzen.co.uk/Tutorial/Arrays.html