I just started studying deep learning, while practicing python basics with numpy assignment, all the test functions are displayed as not defined.“name ‘image2vector_test’ is not defined
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That simply means you have not run the earlier cells in the notebook that import those functions. Try “Cell → Run All Above” and then it should work.
There is a topic about that on the DLS FAQ Thread, which is worth a scan if you’re just getting started here to understand what is covered there.