def my_det(X):
    '''
    Parameters
    ----------
    X : array_like

    Returns
    -------
    det : float
        Determinant of `a`.
    '''

    # Your code here
    X1 = X.copy()
    if X1.shape[0] != X1.shape[1]:
        raise ValueError('Not square')
    det = 1
    for j in range(X1.shape[1]):
        k = j
        for i in range(j + 1, X1.shape[0]):
            if abs(X1[i, j]) > abs(X1[k, j]):
                k = j
        if X1[k, j] == 0:
            det = 0
            return 0
        if X1[j, j] == 0:
            det = 0
            return 0
        X1[k,:], X1[j,:] = X1[j,:].copy(), X1[k,:].copy()
        if k != j:
            det = -det
        try:
            det *= X1[j, j]
        except RuntimeError:
            return 0
        if abs(det) < 1e-7:
            return 0
        for i in range(j + 1, X1.shape[0]):
            try:
                X1[j, i] /= X1[j, j]
            except RuntimeError:
                return inf
        for i in range(X1.shape[0]):
            tmp = X1[i, j]
            if j != i and X1[i, j] != 0:
                X1[i,j+1:] -= X1[j,j+1:] * tmp
                #for k in range(j + 1, X1.shape[0]):
                #    X1[i, k] -= X1[j, k] * X1[i, j]
    return det