问题:
形如,对比a_1和b_1,找出b_1中缺失的数
a_1 = [5, 9, 6, 7, 2, 8, 1, 4, 3, 0]
b_1 = [5, 9, 6, 7, 9, 3, 4, 5, 9, 3]
b_miss = [None if b_1.__contains__(j) else j for i, j in enumerate(a_1)]
b_filter = filter(None, b_miss)
b_miss_filter = list(b_filter)
# 希望预期结果
b_miss_filter = [2, 8, 1, 0]
# 实际结果却为
b_miss_filter = [2, 8, 1]
原因:
filter(None, a)函数进行数据过滤空值None,默认会把0、false这样具体的值过滤掉。
解决:
a_1 = [5, 9, 6, 7, 2, 8, 1, 4, 3, 0]
b_1 = [5, 9, 6, 7, 9, 3, 4, 5, 9, 3]
b_miss = [None if b_1.__contains__(j) else j for i, j in enumerate(a_1)]
b_filter = filter(lambda x: x is not None, b_miss) # 将None换为过滤规则函数
b_miss_filter = list(b_filter)
用函数方式去定义过滤规则,其中,lambda形式比较简洁。