👉 A mapper in programming refers to a function that takes an input data structure (usually a map) and outputs a new map with some transformation applied. The transformation can be any operation or method that maps from one type of data to another.
For example, consider a scenario where we want to map a list of numbers into a dictionary, where the keys are the original numbers and the values are their squares:
```python
def square_numbers(numbers):
return {num: num
2 for num in