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Python之第十四天的努力--函数与迭代器练习

2020-06-14 20:54:26 作者：互联网

01 内容回顾

可迭代对象：
- 可以更新迭代的实实在在的值
- 内部含有
```
'__iter__'
```
  方法的。
- str list tuple dict set range
- 优点：操作方法多，操作灵活，直观
- 缺点：占用内存。
迭代器：
- 可更新迭代的一个工具（数据结构）。
- 内部含有
```
'__iter__'   '__next__'
```
  方法的
- 文件句柄
- 优点：节省内存。惰性机制。
- 缺点：不直观，速度相对慢，操作方法单一，一条路走到黑。
格式化输出。
函数名的应用。

02 练习

# 1.请写出下列代码的执行结果：
# 例一：
#
# def func1():
#     print('in func1' )
#
# def func2():
#     print('in func2' )
#
# ret = func1
# ret()
# ret1 = func2
# ret1()
# ret2 = ret
# ret3 = ret2
# ret2()
# ret3()

# 执行结果：
# in func1
# in func2
# in func1
# in func1

#  例二：
#
# def func1():
#     print('in func1' )
#
# def func2():
#     print('in func2' )
#
# def func3(x, y):
#     x()
#
#     print('in func3' )
#
#     y()
#
# print(111)
# func3(func2, func1)
# print(222)
# 执行结果：
# 111
# in func2
# in func3
# in func1
# 222

#  例三（选做题）：
#
# def func1():
#     print('in func1' )
#
# def func2(x):
#     print('in func2' )
#     return x
#
# def func3(y):
#     print('in func3' )
#     return y
#
# ret = func2(func1)
# ret()
# ret2 = func3(func2)
# ret3 = ret2(func1)
# ret3()
#
# 执行结果：
# in func2
# in func1
# in func3
# in func2
# in func1



# 2.看代码写结果：
#
# def func(arg):
#     return arg.replace('苍老师', '***')
#
#
# def run():
#     msg = "Alex的女朋友苍老师和大家都是好朋友"
#     result = func(msg)
#     print(result)
#
#
# run()

# Alex的女朋友***和大家都是好朋友

# def func(arg):
#     return arg.replace('苍老师', '***')
#
#
# def run():
#     msg = "Alex的女朋友苍老师和大家都是好朋友"
#     result = func(msg)
#     print(result)
#
# data = run()
# print(data)

# Alex的女朋友***和大家都是好朋友
# None



# 3.看代码写结果：
#
# DATA_LIST = []
#
#
# def func(arg):
#     return DATA_LIST.insert(0, arg)
#
#
# data = func('绕不死你')
# print(data)
# print(DATA_LIST)

# None
# ['绕不死你']



# 4.看代码写结果：
#
# def func():
#     print('你好呀')
#     return '好你妹呀'
#
#
# func_list = [func, func, func]
#
# for item in func_list:
#     val = item()
#     print(val)

# 你好呀
# 好你妹呀
# 你好呀
# 好你妹呀
# 你好呀
# 好你妹呀



# 5.看代码写结果：
#
# def func():
#     print('你好呀')
#     return '好你妹呀'
#
#
# func_list = [func, func, func]
#
# for i in range(len(func_list)):
#     val = func_list[i]()
#     print(val)

# 你好呀
# 好你妹呀
# 你好呀
# 好你妹呀
# 你好呀
# 好你妹呀



# 6.看代码写结果：
# def func():
#     return '烧饼'
#
#
# def bar():
#     return '豆饼'
#
#
# def base(a1, a2):
#     return a1() + a2()
#
#
# result = base(func, bar)
# print(result)

# 烧饼豆饼



# 7.看代码写结果：
# for item in range(10):
#     print(item)
#
# print(item)

# 0
# 1
# 2
# 3
# 4
# 5
# 6
# 7
# 8
# 9
# 9



# 8.看代码写结果：
# def func():
#     for item in range(10):
#         pass
#     print(item)
# func()

# 9



# 9.看代码写结果：
# item = '老男孩'
# def func():
#     item = 'alex'
#     def inner():
#         print(item)
#     for item in range(10):
#         pass
#     inner()
# func()

# 9



# 10.看代码写结果：
# l1 = []
# def func(args):
#     l1.append(args)
#     return l1
# print(func(1))
# print(func(2))
# print(func(3))

# [1]
# [1,2]
# [1,2,3]



# 11.看代码写结果：
# name = '太白'
# def func():
#     global name
#     name = '男神'
# print(name)
# func()
# print(name)

# 太白
# 男神



# 12.看代码写结果：
# name = '太白'
# def func():
#     print(name)
# func()

# 太白



# 13.看代码写结果：
# name = '太白'
# def func():
#     print(name)
#     name = 'alex'
# func()

# 报错



# 14.看代码写结果：
# def func():
#     count = 1
#     def inner():
#         nonlocal count
#         count += 1
#         print(count)
#     print(count)
#     inner()
#     print(count)
# func()

# 1
# 2
# 2



# 15.看代码写结果：
# def extendList(val,list=[]):
#  list.append(val)
#  return list
#
# list1 = extendList(10)
# list2 = extendList(123,[])
# list3 = extendList('a')
#
# print('list1=%s'%list1)
# print('list2=%s'%list2)
# print('list3=%s'%list3)

# list1=[10,'a']
# list1=[123]
# list1=[10,'a']



# 16.看代码写结果：
# def extendList(val,list=[]):
#  list.append(val)
#  return list
# print('list1=%s'% extendList(10))
# print('list2=%s'% extendList(123,[]))
# print('list3=%s'% extendList('a'))

# list1=[10]
# list1=[123]
# list1=[10,'a']



# 17.写代码：用while循环模拟for内部的循环机制
# l1 = [1,2,3,4,5,6,7,8,9,10]
#
# obj = iter(l1)
# while 1:
#     try:
#         print(next(obj))
#     except StopIteration:
#         break



# 18.写函数，传入n个数，返回字典{‘max’:最大值,’min’:最小值}
# 例如:min_max(2,5,7,8,4) 返回:{‘max’:8,’min’:2}(此题用到max(),min()内置函数)
# dic = {}
# def min_max(*args):
#     dic['max'] = max(args)
#     dic['min'] = min(args)
#     print(dic)
# min_max(2,5,7,8,4)



# 19.写函数，传入一个参数n，返回n的阶乘
# 例如:cal(7) 计算7654321
# def factorial(num):
#     result = 1
#     while 1:
#         if num > 0:
#             result = result * num
#         else:
#             break
#         num = num - 1
#     return result
# print(factorial(3))

# def factorial(num):
#     result = 1
#     for i in range(num,0,-1):
#         result = result * i
#     return result
# print(factorial(3))



# 20.写函数，返回一个扑克牌列表，里面有52项，每一项是一个元组(选做题)
# 例如：[(‘红心’，2),(‘草花’，2), …(‘黑桃’，‘A’)]
# l1 = []
# def poker():
#     tu1 = ()
#     tu2 = ()
#     tu3 = ()
#     tu4 = ()
#     s1 = 'JQKA'
#     for i in range(2,11):
#         tu1 = ('红心',i)
#         tu2 = ('草花',i)
#         tu3 = ('方片',i)
#         tu4 = ('黑桃',i)
#         l1.append(tu1)
#         l1.append(tu2)
#         l1.append(tu3)
#         l1.append(tu4)
#     for j in s1:
#         tu1 = ('红心', j)
#         tu2 = ('草花', j)
#         tu3 = ('方片', j)
#         tu4 = ('黑桃', j)
#         l1.append(tu1)
#         l1.append(tu2)
#         l1.append(tu3)
#         l1.append(tu4)
# poker()
# print(l1)

# def poker():
#     num = list(range(2, 11))
#     num.extend('JQKA')
#     color = ('红心', '草花', '方片', '黑桃')
#     card = [(m, n) for m in color for n in num]
#     return card
# print(poker())

标签：func1,return,迭代,Python,第十四天,func,l1,print,def
来源： https://www.cnblogs.com/szheng/p/13126869.html