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)
不是
1:内置 2:赋值 3:局部 4:全局
1 def func1(a, b, c, d, e, f): 2 '''返回参数a,b,c,d,e,f构成的列表 3 默认,参数按位置传递; 也支持关键字传递 4 ''' 5 return [a,b,c,d,e,f] 6 def func2(a, b, c,*, d, e, f): 7 ''' 8 返回参数a,b,c,d,e,f构成的列表 9 *后面的参数只能按关键字传递 10 ''' 11 return [a,b,c,d,e,f] 12 def func3(a, b, c, /, d, e, f): 13 ''' 14 返回参数a,b,c,d,e,f构成的列表 15 /前面的参数只能按位置传递 16 ''' 17 return [a,b,c,d,e,f] 18 print( func1(1,9,2,0,5,3) ) 19 print( func1(a=1, b=9, c=2, d=0, e=5, f=3) ) 20 print( func1(1,9,2, f=3, d=0, e=5)) 21 22 print( func2(11, 99, 22, d=0, e=55, f=33) ) 23 print( func2(a=11, b=99, c=22, d=0, e=55, f=33) ) 24 25 print( func3(111, 999, 222, 0, 555, 333)) 26 print( func3(111, 999, 222, d=0, e=555, f=333) )
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 :para: a,b,c: int 方程系数 5 :return: tuple 6 ''' 7 delta = b*b - 4*a*c 8 delta_sqrt = abs(delta)**0.5 9 p1 = -b/2/a; 10 p2 = delta_sqrt/2/a 11 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 print(solve.__doc__) 23 while True: 24 try: 25 a,b,c = eval(input('Enter eqution coefficient: ')) 26 if a == 0: 27 raise 28 except: 29 print('invalid input, or, a is zero') 30 break 31 else: 32 root1, root2 = solve(a, b, c) 33 print(f'root1 = {root1:.2f}, root2 = {root2:.2f}') 34 print()
1 def list_generator (begin,end,step=1): 2 list=[] 3 while begin<=end: 4 list.append(begin) 5 begin=begin+step 6 return list 7 8 list1=list_generator(-5, 5) 9 print(list1) 10 11 list2=list_generator(-5, 5, 2) 12 print(list2) 13 14 list3=list_generator(1, 5, 0.5) 15 print(list3)
1 def is_prime(n): 2 if n < 2: 3 return False 4 for i in range(2,int(n**0.5)+1): 5 if n % i == 0: 6 return False 7 return True 8 9 h=[i for i in range(21)] 10 for x in h[::2]: 11 for a in range(0,21): 12 if is_prime(a) is True: 13 if is_prime(x-a) is True: 14 print(f'{x}={a}+{x-a}') 15 break 16 else: 17 a+=1 18 else: 19 a+=1
1 def encoder(strs): 2 a=list(strs) 3 i=0 4 while i <len(strs): 5 b = ord(a[i]) 6 if 65<=b<=85 or 97<=b<=117: 7 c=chr(b+5) 8 9 elif 85<=b<=90 or 117<=b<=122: 10 c=chr(b-21) 11 else: 12 c=chr(b) 13 a[i]=c 14 i+=1 15 return ''.join(a) 16 17 18 19 def decoder(strs): 20 a = list(strs) 21 i=0 22 while i < len(strs): 23 b = ord(a[i]) 24 if 70<=b<=90 or 102<=b<=122: 25 c=chr(b-5) 26 elif 65<=b<=70 or 97<=b<=102: 27 c=chr(b+21) 28 else: 29 c=chr(b) 30 a[i] = c 31 i+=1 32 return ''.join(a) 33 34 a=input('输入英文文本: ') 35 print(f'编码后的文本:{encoder(a)}') 36 print(f'对编码后的文本解码:{decoder(encoder(a))}')
1 def collatz(n): 2 x=[n] 3 while n!=1: 4 if n%2==0: 5 n=n/2 6 else: 7 n=3*n+1 8 x.append(int(n)) 9 return x 10 try: 11 n=int(input('Enter a positive integer:')) 12 if n<=0: 13 raise 14 except: 15 print('Error: must be a positive integer') 16 else: 17 print(collatz(n))