Visualizing decision tree not using graphviz/web

Question

Due to some restriction I cannot use graphviz , webgraphviz.com to visualize decision tree (work network is closed from the other world).

Question: Is there some alternative utilite or some Python code for at least very simple visualization may be just ASCII visualization of decision tree (python/sklearn) ?

I mean, I can use sklearn in particular: tree.export_graphviz( ) which produces text file with tree structure, from which one can read a tree, but doing it by "eyes" is not pleasant ...

PS Pay attention that

graph = pydotplus.graph_from_dot_data(dot_data.getvalue())  
Image(graph.create_png())

will NOT work, since create_png uses implicitly graphviz