Polars Dataframe Commands (Continued)

20th chunk of `book/dataframes.md`

1b56a0d6cb18238503d41d6d22ce6472a1c2ac927585987000000001000008f0

| polars set             | dataframe             | Sets value where given mask is true.                                                             |                         |
| polars set-with-idx    | dataframe             | Sets value in the given index.                                                                   |                         |
| polars shape           | dataframe             | Shows column and row size for a dataframe.                                                       |                         |
| polars shift           | dataframe             | Shifts the values by a given period.                                                             |                         |
| polars slice           | dataframe             | Creates new dataframe from a slice of rows.                                                      |                         |
| polars sort-by         | dataframe             | Sorts a lazy dataframe based on expression(s).                                                   | sort                    |
| polars std             | expression, dataframe | Creates a std expression for an aggregation of std value from columns in a dataframe.            |                         |
| polars store-get       | any, any              | Gets a Dataframe or other object from the plugin cache.                                          |                         |
| polars store-ls        |                       | Lists stored dataframes.                                                                         |                         |
| polars store-rm        | any                   | Removes a stored Dataframe or other object from the plugin cache.                                |                         |
| polars str-lengths     | dataframe             | Get lengths of all strings.                                                                      |                         |
| polars str-slice       | dataframe             | Slices the string from the start position until the selected length.                             |                         |
| polars strftime        | dataframe             | Formats date based on string rule.                                                               |                         |

Title: Polars Dataframe Commands (Continued)

Summary

This section continues the list of Polars dataframe commands: `set` (sets value where mask is true), `set-with-idx` (sets value at a given index), `shape` (shows column and row size), `shift` (shifts values by a period), `slice` (creates a dataframe slice), `sort-by` (sorts by expression), `std` (creates a standard deviation expression), `store-get` (gets from plugin cache), `store-ls` (lists stored dataframes), `store-rm` (removes from plugin cache), `str-lengths` (gets string lengths), `str-slice` (slices a string), and `strftime` (formats date).