实验4 函数与异常处理编程

发布时间 2023-05-22 22:29:54作者: 超音速老飞机

task1.py

运行代码:

 1 print(sum)
 2 sum = 42
 3 print(sum)
 4 
 5 def inc(n):
 6     sum = n + 1
 7     print(sum)
 8     return sum
 9 
10 sum = inc(7) + inc(7)
11 print(sum)

运行结果:

问题:不是,line1是build-in function sum,line3是指引入的sum = 42,line7是指sum = n + 1,line11是指sum = Inc(7)+ Inc(7)

task2_1.py

 1 def func1(a,b,c,d,e,f):
 2     '''
 3     返回参数a,b,c,d,e,f构成的列表
 4     默认,参数按位置传递;也支持关键字传递
 5     '''
 6     return [a,b,c,d,e,f]
 7 
 8 
 9 def func2(a,b,c,*,d,e,f):
10     '''
11     返回参数a,b,c,*,d,e,f构成的列表
12     *后面的参数只能按关键字传递
13     '''
14     return[a,b,c,d,e,f]
15 
16 
17 def func3(a,b,c,/,d,e,f):
18     '''
19     返回参数a,b,c,d,e,f构成的列表
20     /前面参数只能按位置传递
21     '''
22     return[a,b,c,d,e,f]
23 
24 
25 # func1调用:按位置传递、按参数传递都可以
26 print(func1(1,9,2,0,5,3))
27 print(func1(a=1,b=9,c=2,d=0,e=5,f=3))
28 print(func1(1,9,2,f=3,d=0,e=5))
29 
30 
31 # func2调用:d,e,f必须按照关键字传递
32 print(func2(11,99,22,d=0,e=55,f=33))
33 print(func2(a=11,b=99,c=22,d=0,e=55,f=33))
34 
35 
36 # func3调用:a,b,c必须按照位置传递
37 print(func3(111,999,222,0,555,333))
38 print(func3(111,999,222,d=0,e=555,f=333))

运行结果:

试错结果:

task2_2.py

运行代码:

1 list1 = [1,9,8,4]
2 
3 print(sorted(list1))
4 print(sorted(list1,reverse = True))
5 print(sorted(list1,True))

运行结果:

问题:需要

task2_3.py

运行代码:

1 def func(a,b,c,/,*,d,e,f):
2     return([a,b,c,d,e,f])
3 print(func(1,2,3,d=4,e=5,f=6))

运行结果:

task3.py

运行代码:

 1 def solve(a,b,c):
 2     '''
 3     求解一元二次方程,返回方程的两个根
 4 
 5     :para:a,b,c:float 方程系数
 6     :return:tuple
 7     '''
 8     delta = b*b - 4*a*c
 9     delta_sqrt = abs(delta)**0.5
10     p1 = -b/2/a
11     p2 = delta_sqrt/2/a
12 
13     if delta >= 0:
14         root1 = p1 + p2
15         root2 = p1 - p2
16     else:
17         root1 = complex(p1,p2)
18         root2 = complex(p1,-p2)
19 
20     return root1,root2
21 
22 
23 while True:
24     try:
25         t = input('输入一二次方程系数a b c,或者,输入#结束:')
26         if t == '#':
27             print('结束计算,退出')
28             break
29         a,b,c = map(float,t.split())
30         if a == 0:
31             raise ValueError('a = 0,不是一元二次方程')
32     except ValueError as e:
33         print(repr(e))
34         print()
35     except:
36         print('有其它错误发生\n')
37     else:
38         root1,root2 = solve(a,b,c)
39         print(f'root1 = {root1:.2f},root2 = {root2:.2f}')
40         print()

运行结果:

 

task4.py

运行代码:

 1 # list_generator()函数定义
 2 # 待补足
 3 # xxx
 4 def list_generator(a,b,c = 1):
 5     list = []
 6     while a <= b:
 7         list.append(a)
 8         a += c
 9     return list
10 
11 
12 
13 list1 = list_generator(-5,5)
14 print(list1)
15 
16 list2 = list_generator(-5,5,2)
17 print(list2)
18 
19 list3 = list_generator(1,5,0.5)
20 print(list3)

运行结果:

 

 task5.py

运行代码:

 1 def is_prime(n):
 2     if n == 2:
 3         return False
 4     else:
 5         for i in range(2,n):
 6             if n % i == 0:
 7                 return False
 8                 break
 9             else:
10                 return True
11 for i in range(4,21,2):
12     for x in range(2,i):
13         if is_prime(x):
14             if (i-x)>1 and is_prime(i-x):
15                 print(f'{i} = {x} + {i-x}')
16                 break

运行结果:

 task6.py

运行代码:

 1 def encoder(text):
 2     text1 = ''
 3     for i in text:
 4         if 'a' <= i <= 'z':
 5             c = 97 + (ord(i) + 5 - 97) % 26
 6             text1 += chr(c)
 7         elif 'A' <= i <= 'Z':
 8             c = 65 + (ord(i) + 5 - 97) % 26
 9             text1 += chr(c)
10         else:
11             text1 += i
12     return text1
13 
14 def decoder(text):
15     text1 = ''
16     for i in text:
17         if 'a' <= i <= 'z':
18             c = 65 + (ord(i) - 5 - 65) % 26
19             text1 += chr(c)
20         elif 'A' <= i <= 'Z':
21             c = 65 + (ord(i) - 5 - 65) % 26
22             text1 += chr(c)
23         else:
24             text1 += i
25     return text1
26 text = input('输入英文文本: ')
27 
28 encoded_text = encoder(text)
29 print('编码后的文本: ', encoded_text)
30 
31 decoded_text = decoder(encoded_text)
32 print('对编码后的文本解码: ', decoded_text)

运行结果:

task7.py

运行代码:

 1 def collatz(n):
 2     x = []
 3     x.append(int(n))
 4     while n != 1:
 5         if n % 2 == 0:
 6             n = n/2
 7             x.append(int(n))
 8         elif n % 2 != 0:
 9             n = n*3 + 1
10             x.append(int(n))
11         else:
12             if n == 1:
13                 x.append(int(n))
14     return x
15 try:
16     n = int(input('Enter a positive integer:'))
17     if n <= 0:
18         raise ValueError
19 except ValueError:
20     print('Error: must be a positive integer')
21 else:
22     print(collatz(n))

运行结果:

task8.py

运行代码:

 1 def func(n):
 2     if n == 0:
 3         return 0
 4     else:
 5         return 2*func(n-1) + 1
 6 
 7 while True:
 8     x = input()
 9     if x == '#':
10         print('计算结束')
11         break
12     n = int(x)
13     ans = func(n)
14     print(f'n = {n}, ans = {ans}')

运行结果: