def categorical(df, remove_ov=True):
    """ Return a list of the columns variable names which types is object or categorical"""
    object_features = df.loc[:, df.dtypes == 'object'].columns.tolist()
    categorical_features = df.loc[:, df.dtypes == 'category'].columns.tolist()
    features = list(set(object_features + categorical_features))
    if remove_ov:
        try:
            features.remove("Survived")
        except ValueError:
            None

    return features