如何创建一个不在Python中立即评估的符号函数执行DAG？

I wanted to create a "symbolic" representation of function calls (in my mind right now the best way to represent this is with a Graph or a DAG or a Tree) i.e. set up an execution graph and then execute the graph later, with the possibility with slightly different inputs or the graph having a completely different state when executed (similarly how TensorFlow does it, with feeds and inputs to the graph). I wanted to create a "symbolic" representation