Call functions recursively in tree structure using python

[dubru]

I am new to python, I need to call functions recursively in tree structure.

I am calling the python function in in for loop by passing A, this will produce the output B in first loop and C in second loop.

here I need to run the same function for B and C, so here B will generate D and E and C will generate F and next Run same python function for D it will generate G so on, I have to run the same until I get null.

How can I write the logic in python

[nilamo]

What have you tried? Show us some code, so we can see how to help.