小学生都能学会的python(<lamda匿名函数,sorted(),filter(),map(),递归函数>)

# def fang(x):
#     return x**2
#
# # ret = fang(5)
# # print(ret)
#
# zrf = lambda x : x**2 # 匿名函数 lambda 参数: 返回值
#
# ret = zrf(10)
# print(ret)
#
# # 给函数传递两个参数a. b 返回a+b的结果
# a = lambda a, b: a+b
# print(a(188,35006))

#
# lst = [1, 8, 18, 19, 97, 12, 3]
# # lst.sort() # lst自带的排序功能
# l2 = sorted(lst) # 排序功能
# print(l2)
#        0         2      2      2       0         2        2       2
lst = ["赵瑞鑫", "刘伟", "刘能", "赵四", "王大拿", "于谦",  "范伟", "沈腾"]

# def func(name):
#     return len(name) % 3 # 返回数字

l2 = sorted(lst, key=lambda name: len(name) % 3)
print(l2)


lst = [{"id": 1, "name": ‘alex‘, "age": 18},
    {"id": 2, "name": ‘wusir‘, "age": 16},
    {"id": 3, "name": ‘taibai‘, "age": 17}]
# 按照年龄对学?信息进?排序
# def func(dic):
#     return dic[‘age‘]
# l2 = sorted(lst, key=func) # 流程: 把可迭代对象的每一项传递给函数. 函数返回一个数字. 根据这个数字完成排序
# print(l2)
# l3 = sorted(lst, key=lambda dic: dic[‘age‘])
# l4 = sorted(lst, key=lambda dic: len(dic[‘name‘]))
# l4 = sorted(lst, key=lambda dic: ascii(dic[‘name‘][0]))  # ord()
# print(l4)

# lst = [23, 28, 15, 27, 24, 22]
# def func(age):
#     return age > 18 and age % 2 == 0
#
# f = filter(lambda age: age > 18 and age % 2 == 0, lst)
# # print(sorted(f))
# # f = filter(func, lst)
# # print(f)
# # print("__iter__" in dir(f))
#
# for el in f:
#     print(el)

# lst = [23, 28, 15, 27, 24, 22]
# f = filter(lambda age: age % 2 == 0, filter(lambda age: age > 18, lst))
# print(list(f))

# lst = [{"id":1, "name":‘alex‘, "age":18},
#  {"id":2, "name":‘wusir‘, "age":16},
#  {"id":3, "name":‘taibai‘, "age":17}]
#
# # 筛选出年龄大于等于17岁的人
# print(list(sorted(filter(lambda dic: dic[‘age‘] >= 17, lst), key=lambda dic: dic[‘age‘])))

# lst = [1,5,9,3]
# # l1 = [i**2 for i in lst]
# m = map(lambda x: x**2, lst)
# print(list(m))

# 计算两个列表相同位置的数据的和
# lst1 = [1, 2, 3, 4, 5]
# lst2 = [2, 4, 6, 8, 10]
#
# print(list(map(lambda x, y: x + y , lst1, lst2)))

# # 递归
# def func():
#     print("我叫李嘉诚")
#     func() # 递归的入口
#
# # 调用函数
# func()

# 用递归实现1-100
# import sys
# sys.setrecursionlimit(5000) # 设置递归的最大深度, 一般不要改.
#
# def func(index):
#     print(index)
#     func(index + 1)
#
# func(1) # 递归的深度: 1000 但是到不了1000, 997 - 998



# 遍历某文件夹内的所有文件和文件夹

import os
# 树形结构的遍历
def func(file_path, ceng):
    # 获取到路径下的所有文件
    lst = os.listdir(file_path) # 得到文件夹里的所有文件和文件夹
    for file in lst: # 文件名
        # 获取到文件的全路径
        full_path = os.path.join(file_path, file) # D:\python学院\s16\第一阶段\day01 认识python 变量 数据类型 条件if语句
        if os.path.isdir(full_path): # 判断这个路径是否是一个文件夹
            print("\t"*ceng, file)
            func(full_path, ceng+1)
        else:
            print("\t"*ceng, file)
    else:
        return
func("D:\python学院\s16\第一阶段", 0)

# 二分法查找的效率特别高.
# 缺点: 有序序列
#
# lst = [1,8,16,32,55,78,89,1,5,4,7,5,9,6,8,5,4,5,44,5,2,1,4,5,1]
# # [1, 1, 1, 1, 2, 4, 4, 4, 5, 5, 5, 5, 5, 5, 6, 7, 8, 8, 9, 16, 32, 44, 55, 78, 89]
# lst = sorted(lst)
# n = int(input("请输入一个数:"))
# left = 0
# right = len(lst) - 1
#
# while left  lst[mid]:
#         left = mid + 1
#     elif n  lst[mid]:
#             new_lst = lst[mid+1:]
#             return func(n, new_lst)
#         elif n  lst[mid]:
            left = mid + 1
        elif n