How can I use the replaceWhere option in Delta Lake to atomically replace records that match a given predicate, and how can I restore data if it has been accidentally overwritten?
You can use the `replaceWhere` option in Delta Lake to atomically replace records that match a given predicate. Here's an example:

```python
replace_data.write \
 .mode("overwrite") \
 .option("replaceWhere", "start_date >= '2017-01-01' AND end_date <= '2017-01-31'") \
 .save("/tmp/delta/events")
```

In this example, `replace_data` is the DataFrame containing the data you want to write, and the `replaceWhere` option specifies the predicate for the records you want to replace. The `save` method writes the data to the Delta Lake table at `/tmp/delta/events`, atomically replacing the records that match the predicate.

If you accidentally overwrite data, you can use the `restore` command to undo the change. Here's an example:

```python
deltaTable.restoreToVersion(123)
```

In this example, `123` is the version number you want to restore to. You can find the version number by querying the Delta Lake table's history. The `restoreToVersion` method restores the table to the state it was in at the specified version, undoing any changes made after that version.