21 lines
520 B
Markdown
21 lines
520 B
Markdown
### count_occurences
|
|
|
|
:information_source: Already implemented via `list.count()`.
|
|
|
|
Counts the occurrences of a value in an list.
|
|
|
|
Uses the `reduce` functin from built-in module `functools` to increment a counter each time you encounter the specific value inside the list.
|
|
|
|
```python
|
|
from functools import reduce
|
|
|
|
|
|
def count_occurences(arr, val):
|
|
return reduce(
|
|
(lambda x, y: x + 1 if y == val and type(y) == type(val) else x + 0),
|
|
arr)
|
|
```
|
|
|
|
```python
|
|
count_occurrences([1, 1, 2, 1, 2, 3], 1) # 3
|
|
``` |