Find the NaNs Hiding in Your Table
isna, sum, and a missingness map.
Why Missing Data Matters
Real datasets are full of gaps. Before any analysis, you need to know where missing values hide, because they quietly skew every result you trust. 🔎
Meet NaN
In pandas, an empty cell usually shows up as NaN, short for Not a Number. It is the standard marker for a value that simply is not there.
All lessons in this course
- Find the NaNs Hiding in Your Table
- Drop vs Fill: Choosing Wisely
- Impute With Mean, Median, or Mode
- Fix dtypes and Duplicate Rows