Visualization of Python’s built-in types 視覺化Python內建型別

利用Graphviz軟體可以將結構性資料用圖形呈現，這裡將以圖形繪製Python內建型別的繼承關係，我使用Graphviz的Python API輸出PNG圖形，程式碼如下：

if __name__ == "__main__":
    import types
    import gv
    g = gv.digraph('types')
    gv.setv(g, 'overlap', 'false')
    gv.setv(g, 'splines', 'true')
    for item in dir(__builtins__):
        attr = getattr(__builtins__, item)
        if type(attr) is types.TypeType and \
           not issubclass(attr, BaseException):
            tail = None
            head = None            
            for i in attr.__mro__:
                nodename = i.__name__
                tail = gv.findnode(g, nodename)
                if not tail:
                    tail = gv.node(g, nodename)
                if head and not gv.findedge(tail, head):
                    gv.edge(tail, head)
                head = tail
    
    gv.layout(g, 'neato')
    gv.render(g, 'png', 'built-in_types.png')

執行完畢之後，將會在程式同一路徑下產生一個檔名為built-in_types的PNG檔。

從這張圖可以看到所有的型別都是繼承至object類別。

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