[SOLVED] Hello I'm keep getting None in printed output of postorder binary tree programme code. How can I fix it? Please help

Question

https://code.sololearn.com/c44p4x83eGFY/?ref=app

Answer 1

print(calculate(root))
postorder(root) #without print

postorder() don't have return explicitly. So implicitly return none. Don't capture it by print.