两个字符串数组的交集(忽略大小写)

def intersection(str_arr1, str_arr2):
    set1 = set(str_arr1)
    set2 = set(str_arr2)
    intersection_set = set1.intersection(set2)
    result = list(intersection_set)
    return result

str_arr1 = ['apple', 'banana', 'orange', 'grape']
str_arr2 = ['apple', 'grape', 'watermelon', 'banana']
result = intersection(str_arr1, str_arr2)
print(result)