Counting longest runs of {0, 1} in binary NumPy array

longest_runs.py

## Source: https://stackoverflow.com/questions/24342047/count-consecutive-occurences-of-values-varying-in-length-in-a-numpy-array/24343375#24343375

def longest_runs_sim(n: int = 50) -> int:
    # Random sequence where each n_i is element of {0, 1}
    seq = np.random.randint(0, 2, n)

    longest_runs = {1: None, 0: None}
    for i, outcome in enumerate([~seq, seq]):
        runs = \
            np.diff( # Diff of indices counts runs
                np.where( 
                    np.concatenate( # Checks if next value is different; if yes, then 1
                        # Note: Concatenation deals with edge cases
                        ([outcome[0]], outcome[:-1] != outcome[1:], [True])
                    )
                )[0] # Returns indices for whenever the value switches
            )[::2] # Only return the diffs for the 1s
        longest_runs[i] = runs.max()

    # Longest runs (0s or 1s)
    return max(longest_runs.values())