| Exercise | Difficulty | Completed? |
|---|---|---|
| Welcome to DataFrames | Elementary | |
| Select columns | Elementary | |
| Select rows by label (.loc) | Elementary | |
| Select rows by position (.iloc) | Elementary | |
| Aggregate a column | Elementary | |
| Creating a new column | Elementary | |
| Modify a column | Elementary | |
| Filter rows | Elementary | |
| Select rows by boolean expressions | Elementary | |
| Conditional column update | Elementary | |
| Bucketing values using cut | Elementary | |
| Map a function over each row | Elementary | |
| Impute missing values | Elementary | |
| Melt a wide table to long table | Elementary | |
| Find NaN rows | Elementary | |
| Preparing a heatmap | Easy | |
| Impute missing values with past mean | Easy | |
| Max of min windows | Easy | |
| Customer Lifespan | Medium | |
| Customer Retention | Medium | |
| Customer Retention Over Time | Medium | |
| Customer Retention By Month Cohort | Medium |