实验四

task1：

print(sum)
sum = 42
print(sum)

def inc(n):
  sum = n+1
  print(sum)
  return sum

sum = inc(7) + inc(7)
print(sum)

截图：

task2-1：

def func1(a, b, c, d, e, f):
  return [a,b,c,d,e,f]


def func2(a, b, c, *, d, e, f):
  return [a, b, c, d, e, f]


def func3(a, b, c, /, d, e, f):
  return [a, b, c, d, e, f]

print( func1(1,9,2,0,5,3) )
print( func1(a=1, b=9, c=2, d=0, e=5, f=3) )
print( func1(1,9,2, f=3, d=0, e=5))

print( func2(11, 99, 22, d=0, e=55, f=33) )
print( func2(a=11, b=99, c=22, d=0, e=55, f=33) )

print( func3(111, 999, 222, 0, 555, 333))
print( func3(111, 999, 222, d=0, e=555, f=333) )

print( func3(111, 999, 222, 0, 555, 333))
print( func3(111, 999, 222, d=0, e=555, f=333) )

截图：

task2-2：

list1 = [1, 9, 8, 4]

print(sorted(list1))
print(sorted(list1,reverse=True))
print(sorted(list1,True))

截图：

task2-3：

def func(a, b, c, /, *, d, e, f):
    return([a,b,c,d,e,f])

x= func(1, 2, 3, d=4, e=5, f=6)
print(x)

截图：

task3：

def solve(a, b, c):
  delta = b*b - 4*a*c
  delta_sqrt = abs(delta)**0.5
  p1 = -b/2/a
  p2 = delta_sqrt/2/a

  if delta >= 0:
     root1 = p1 + p2
     root2 = p1 - p2
  else:
     root1 = complex(p1, p2)
     root2 = complex(p1, -p2)

  return root1, root2


print(solve.__doc__)
while True:
  try:
    t = input('输入一元二次方程系数a b c, 或者，输入#结束: ')
    if t == '#':
      print('结束计算，退出')
      break
    a, b, c = map(float, t.split())
    if a == 0:
      raise ValueError('a = 0, 不是一元二次方程')
  except ValueError as e:
    print(repr(e))
    print()
  except:
    print('有其它错误发生\n')
  else:
    root1, root2 = solve(a, b, c)
    print(f'root1 = {root1:.2f}, root2 = {root2:.2f}')
    print()

截图：

task4：

def list_generator(start, stop, step=1):
    result = []
    i = start
    while i <= stop:
         result.append(i)
         i += step
    return result

list1 = list_generator(-5, 5)
print(list1)
list2 = list_generator(-5, 5, 2)
print(list2)
list3 = list_generator(1, 5, 0.5)
print(list3)

截图：

task5：

def is_prime(n):
    if n<=1:
        return False
    for i in range(2,int(n**0.5)+1):
        if n%i == 0:
            return False
    return True

def golbdach(n):
    for i in range(2,n):
        if is_prime(i):
            j = n - i
            if is_prime(j):
                return i,j
    return None

for i in range(4,22,2):
    x = golbdach(i)
    if x:
        print(f"{i}={x[0]}+{x[1]}")

截图·：

task6：

def encoder(text):
    result = ""
    for i in text:
        if 65 <= ord(i) <= 90:
            x = (ord(i) - ord('A')+5)%26 +ord('A')
            ans = chr(x)
            result += ans
        elif 97 <= ord(i) <= 122:
            x = (ord(i) - ord('a')+5)%26 + ord('a')
            ans = chr(x)
            result += ans
        else:
            result += i
    return result

def decoder(text):
    result = ""
    for i in text:
        if 65 <= ord(i) <= 90:
            x = (ord(i) - ord('A')-5)%26 +ord('A')
            ans = chr(x)
            result += ans
        elif 97 <= ord(i) <= 122:
            x = (ord(i) - ord('a')-5)%26 + ord('a')
            ans = chr(x)
            result += ans
        else:
            result += i
    return result

text = input('输入英文文本: ')
encoded_text = encoder(text)
print('编码后的文本: ', encoded_text)
decoded_text = decoder(encoded_text)
print('对编码后的文本解码: ', decoded_text)

截图：

task7：

def  collatz(n):
    if n % 2 == 0:
        return n//2
    else:
        return n*3 +1

result_list = []
try:
    n = int(input('Enter a positive integer:'))
    if n <= 0:
        raise ValueError('must be a positive integer')
    while n != 1:
        result_list.append(n)
        n = collatz(n)
    result_list.append(1)
except ValueError:
    print("Error: must be a positive integer")
else:
    print(result_list)

截图

task8：

def func(n):
    if n == 0:
        return 0
    return func(n-1)*2 +1

while True:
    x = input()
    if x == '#':
        print('计算结束')
        break
    n = int(x)
    ans = func(n)
    print(f'n m= {n},ans = {ans}')

截图：