To count the number of elements in an array matching a condition in Python 3.10, we can use the built-in sum() function along with a list comprehension to create a boolean array representing whether each element in the array satisfies the condition. We can then pass this boolean array to sum(), which will add up all the True values and return the total count.
Here's an example code snippet to demonstrate this approach:
# create a sample array of integers
arr = [2, 4, 6, 8, 10, 12]
# count the number of even numbers in the array
count = sum([num % 2 == 0 for num in arr])
# print the result
print(f"There are {count} even numbers in the array.")
In this example, we create an array arr containing the integers 2 through 12. We then use a list comprehension [num % 2 == 0 for num in arr] to create a boolean array where each value is True if the corresponding element in arr is even (i.e., has no remainder when divided by 2), and False otherwise. We pass this boolean array to sum(), which adds up all the True values and returns the count of even numbers in the array. The output of this code will be:
There are 6 even numbers in the array.
You can modify the condition in the list comprehension to count any other subset of elements matching your desired criteria.