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    1.

    1. names = ["jerry", "hansen", "qianan", "Wendy", "Tom", "bob"]
    2. #filter(func,iterable) 过滤  
    3. #type(filter) 为<class 'filter'> 需要强转为列表
    4. names1 = list(filter(lambda x: len(x) <= 3, names))     #过滤出小于等于3的元素
    5. # names2 = []
    6. # for s in names:
    7. #     if s not in names1:
    8. #         s = s.upper()
    9. #         names2.append(s)
    10. names2 = [i.upper() for i in names if i not in names1]
    11. print(names2)
    13. #优化：
    14. names2 = [i.upper() for i in names if len(i)>3]

    2.

    1. li1 = [i for i in range(0,5,2)] 
    2. li2 = [i for i in range(1,5,2)]
    3. li3 = [(i, j) for i in li1 for j in li2]
    4. print(li3)
    6. #优化：
    7. #li = [(i,j) for i in range(0,5,2) for j in range(1,5,2)]

    3.

    1. names = ['Bob', 'JOHN', 'alice', 'bob', 'ALICE', 'James', 'Bob', 'JAMES', 'jAMeS']、
    2. #new_names = []  
    3. #for i in names:
    4. #    new_names.append(i.capitalize())  #str.capitalize()首字母大写
    5. new_names = [i.capitalize() for i in names]  
    6. new_names = list(set(new_names))    #去重
    7. print(new_names)
    9. #优化：
    10. #new_names = {i.capitalize() for i in names}