# Introduction In this lab, you will learn about the `asof()` method in the Pandas library of Python. The `asof()` method is used to retrieve the last row or rows without any NaN values before a specified date or index location in a DataFrame. ## VM Tips After the VM startup is done, click the top left corner to switch to the **Notebook** tab to access Jupyter Notebook for practice. Sometimes, you may need to wait a few seconds for Jupyter Notebook to finish loading. The validation of operations cannot be automated because of limitations in Jupyter Notebook. If you face issues during learning, feel free to ask Labby. Provide feedback after the session, and we will promptly resolve the problem for you.
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