Count Distinct Groups

← Count Distinct Groups easy

dplyr

Write an R function solution(x) that uses dplyr to return the number of distinct values in the column group of the data frame x.

Example

df <- data.frame(group = c("a", "b", "a", "c"))
solution(df)  →  3

solution.py

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📊 Test Results

Run your code to see test results here.

Every challenge runs your code by calling a function. You must define a function named solution(...) that returns the answer.

Key rule: use return — not print(). The grader only checks the returned value; anything you print is ignored.

✗ Won't be graded

def solution(a, b):
    print(a + b)

✓ Correct

def solution(a, b):
    return a + b

Your function is called with the challenge's test inputs, for example:

solution(3, 5)   # expects 8

Match the parameter names and count shown in the challenge description, and always finish with a return.