Python教程5
1.公共方法
# -*-coding:utf-8-*-a = [1, 2, 3]# del 的两种用法del a[1]print(a)del (a[1])print(a)del (a)# len方法a1 = [1, 2, 3]print(len(a1))# 返回容器中元素的最大/最小值,如果是字典则针对Key比较大小t_str = "jw1qeyhwoqjdxjwlomz"print(max(t_str)) # 返回容器最大值print(min(t_str)) # 返回容器中最小值t_dict = { "a": "z", "b": "y", "c": "x"}print(max(t_dict))print(min(t_dict))# 字符串,列表,元组切片,不能针对字典切片(字典是无序的集合,用键值对保存值)print([0, 1, 2, 3][1:3])print((0, 1, 2, 3, 4)[1:4])# 公共运算符 */+print([1, 2] * 5) # 列表和元组,字符串都适用print([1, 2] + [3]) # 列表和元组,字符串都适用t1 = [1, 2, 3, 4]t2 = [5, 6]t3 = [11, 12]print(t1 + t2)t1.extend(t3) # 注意不能写print(t1.extend(t3))print(t1)t1.append(0) # append()方法是追加元素,注意追加的类型print(t1)t1.append([44, 55]) # 输出则是[1, 2, 3, 4, 11, 12, 0, [44, 55]]print(t1)# 成员运算符 in 和not in 列表和元组,字符串,字典(key)都适用print("a" in "ancd") # 表示a包含再字符串ancd ,print("c" not in "dsfdwfxc")# 完整的for循环方法,for num in [1, 2, 3, 4, 5]: print(num) if num == 3: breakelse: # 默认情况下,列表循环遍历完就会执行 print("会执行嘛")print("循环结束")# for完整循环应用的场景""""搜索时,完全遍历未找到目标,希望给出提示时,采用else"""student = [ { "name": "啊土"}, { "name": "小美"}]find_name = "啊土1"for stu_dict in student: print(stu_dict) if stu_dict["name"] == find_name: print("找到啦%s" % find_name) break # 找到了,就不需要后续的遍历了else: print("抱歉,没有找到%s" % find_name) # 如果遍历完都找不到print("循环结束啦!")
2.综合应用