# Introduction In this lab, we will learn how to use the `DataFrame.isnull()` method in pandas. This method is used to detect missing values in a DataFrame. By applying this method to a DataFrame, it returns a DataFrame of boolean values, where True indicates that the element is a null value and False indicates that the element is not a null value. It's important to note that this method does not consider empty strings or `numpy.inf` as null values. ## 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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