一、递归访问目录： 且目录中嵌套目录，有层次的列出给定目录中所有的文件和文件夹
def listdir(path, count=0): list_dir = os.listdir(path) for i in list_dir: path1 = os.path.join(path + "/", i) if os.path.isdir(path1): print(count * " ", i) count1 = count + 1 listdir(path1, count1) else: print(count * ' ', i) listdir('D:test') # 输出 1.txt 2.txt test1 1.txt 2.txt test2 1.txt
二、定义一个嵌套函数， 外层函数打印this is outing function，内层函数功能:打印This is inner function
def outer(): print("this is outing function ") def inner(): print("This is inner function") return inner f_inner = outer() f_inner() # 输出 this is outing function This is inner function
三、定义一个递归函数：
打印斐波那契数列
斐波那契数列指的是这样一个数列 0, 1, 1, 2, 3, 5, 8, 13,特别指出：第0项是0，第1项是第一个1。从第三项开始，每一项都等于前两项之和。
def fib(n): if n == 0: return [0] if n == 1: return [0, 1] if n == 2: return [0, 1, 1] fibs = [0, 1, 1] for i in range(2, n): fibs.append(fibs[-1] + fibs[-2]) return fibs print(fib(10)) # 输出 [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]
四、对列表进行排序:
list_data = [“grape”, “peach”, “berry”, “pineapple”, “apple”, “strayberry”, “watermelon”] 排序规则：按照最后一个字符进行排序，如果最后一个字符相等，按照第一个字符排序
list_data = ["grape", "peach", "berry", "pineapple", "apple", "strayberry", "watermelon"] def data(x): return [-1] print(list_data) list_data.sort(key=lambda x: x[-1]) print(list_data) # 输出 ['grape', 'peach', 'berry', 'pineapple', 'apple', 'strayberry', 'watermelon'] ['grape', 'pineapple', 'apple', 'peach', 'watermelon', 'berry', 'strayberry']
五、利用map函数： 计算三个列表，相同位置元素之和
list1 = [1, 2, 3] list2 = [4, 5, 6] list3 = [7, 8, 9] map_obj = map(lambda x, y, z: x + y + z, list1, list2, list3) print(list(map_obj)) # 输出 [12, 15, 18]
六、利用filter函数过滤列表中所有带a的字符串
list_data = ["grape", "what", "which", "you", "friend", "am"] filter_obj = filter(lambda x: 'a' not in x, list_data) print(list(filter_obj)) # 输出 5050
