About the error during the Linux

[Mingshan-Beal]

I have run the code at this environment.
OS: Ubuntu 20.04
Python: 3.8.5

I have already installed the Graphviz but I have following error. Please help me. Thanks.

Error:
python3 dotnets.py | dot -Tpng
�PNG

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[Martin Isaksson]

You need to redirect the output, either to a file or to a viewer.
For example

python3 dotnets.py | dot -Tpng > output.png

[Mingshan-Beal]

Yeah, it works. Thank you.