实验四、函数与异常处理编程

任务一

print(sum)
sum=42
print(sum)

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

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

任务二

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))

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

任务三

def solve(a,b,c):
    '''求解一元二次方程，返回方程的两个根

    ：para：a,b,c:float 方程系数
    :return:tuple
    '''
    delta = b*b - 4*a*c
    delta_sqrt = abc(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('结束运算，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('有其他错误发生\n')
    else:
        root1,root2 = solve(a,b,c)
        print(f'root1 = {root1:.2f},root2 = {root2:.2f}')
        print()

任务四

def list_generator(a,b,c):
    ls = [a]
    while a<b:
        a = a+c
        ls.append(a)
    print(ls)

list_generator(-5,5,2)

任务五

def is_prime(n):
    import math
    m = 0
    for i in range(2, int(math.sqrt(n)) + 1):
        if n % i == 0:
            m += 1
        else:
            m += 0
    if m != 0:
        result = False
    else:
        result = True
    return result

for i in range(4,21,2):
    for j in range(2,i):
        if is_prime(j) == True:
            k = i - j
            if is_prime(k) == True:
                print(f'{i} = {j} + {k}')
                break

任务六

def encoder(text):
    text1 = ''
    for i in text:
        if 'a' <= i <= 'z':
            c = 97 + (ord(i) + 5 - 97) % 26
            text1 += chr(c)
        elif 'A' <= i <= 'Z':
            c = 65 + (ord(i) + 5 - 65) % 26
            text1 += chr(c)
        else:
            text1 += i
    return text1

def decoder(text):
    text1 = ''
    for i in text:
        if 'a' <= i <= 'z':
            c = 97 + (ord(i) - 5 - 97) % 26
            text1 += chr(c)
        elif 'A' <= i <= 'Z':
            c = 65 + (ord(i) - 5 - 65) % 26
            text1 += chr(c)
        else:
            text1 += i
    return text1

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)

任务七

def collatz(n):
    lst = []
    lst.append(n)
    while n != 1:
        if n %2 == 0:
            n = n/2
            lst.append(int(n))
        else:
            n = n*3 +1
            lst.append(int(n))
    return lst
try:
    n = int(input('Enter a positive integer:'))
    if n <= 0:
        raise ValueError
except ValueError:
    print('Error: must be a positive integer')
else:
    print(collatz(n))

任务八

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

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