实验四

 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)

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

1 print(func2(11,99,22,0,55,33))

1 print(func3(a=111,b=999,c=222,0,555,333))

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

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

 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 while True:
23     try:
24         t = input('输入一元二次方程系数a b c,或者，输入#结束：')
25         if t == '#':
26             print('结束计算，退出')
27             break
28         a,b,c = map(float,t.split())
29         if a == 0:
30             raise ValueError('a = 0，不是一元二次方程')
31     except ValueError as e:
32         print(repr(e))
33         print()
34     except:
35         print('有其他错误发生\n')
36     else:
37         root1,root2 = solve(a,b,c)
38         print(f'root1 = {root1:.2f},root2 = {root2:.2f}')
39         print()

1 print(solve.__doc__)

 1 def list_genarator(a,b,c=1):
 2     if c % 1 == 0:
 3         return list(range(a,b+1,c))
 4     else:
 5         list0 = []
 6         while a <= b:
 7             list0.append(a)
 8             a = a + c
 9         return list0
10 
11 list1 = list_genarator(-5,5)
12 print(list1)
13 
14 list2 = list_genarator(-5,5,2)
15 print(list2)
16 
17 list3 = list_genarator(1,5,0.5)
18 print(list3)

 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 
12 lst1 = []
13 for i in range(4,21,2):
14     for j in range(1,i):
15         m = i - j
16         if is_prime(j) and is_prime(m) and j <= m:
17             print(f'{i} = {j} + {m}')
18             break

 1 def encoder(text):
 2     text1 = ''
 3     for i in text:
 4         if 'a' <= i <='z':
 5             i = chr((ord(i)-97+5)%26 + 97)
 6         elif 'A' <= i <= 'Z':
 7             i = chr((ord(i)-65+5)%26 + 65)
 8         text1 += i
 9     return text1
10 
11 
12 def decoder(text):
13     text2 = ''
14     for i in text:
15         if 'a' <= i <='z':
16             i = chr((ord(i)-97-5)%26 + 97)
17         elif 'A' <= i <= 'Z':
18             i = chr((ord(i)-65-5)%26 + 65)
19         text2 += i
20     return text2
21 
22 text = input('输入英文文本: ')
23 encoded_text = encoder(text)
24 print('编码后的文本: ', encoded_text)
25 
26 decoded_text = decoder(encoded_text)
27 print('对编码后的文本解码: ', decoded_text)

 1 def collatz(n):
 2     lst1=[n]
 3     while True:
 4         if n==1:
 5             break
 6         if n%2==0:
 7             n=int(n/2)
 8             lst1.append(n)
 9         else:
10             n=3*n+1
11             lst1.append(n)
12     return lst1
13 n=input('Enter a positive intefer:')
14 try:
15     n=int(n)
16     if n<=0 :
17         raise
18 except:
19     print('Error: must be a positive integer')
20 else:
21     print(collatz(n))

 1 def func(n):
 2     if n == 1:
 3         return 1
 4     elif n > 1:
 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}')