实验四 函数与异常处理编程

task1

实验源码

print(sum)
sum = 42
print(sum)

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

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

 

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 答：不是

1. line1  2. line2~line3  3. line5~line8  4. line10~line11

 

task2_1

实验源码

def func1(a, b, c, d, e, f):
    '''
    返回参数a,b,c,d,e,f构成的列表
    默认，参数按位置传递; 也支持关键字传递
    '''
    return [a, b, c, d, e, f]

def func2(a, b, c,*, d, e, f):
    '''
    返回参数a,b,c,d,e,f构成的列表
    *后面的参数只能按关键字传递
    '''
    return [a, b, c, d, e, f]

def func3(a, b, c, /, d, e, f):
    '''
    返回参数a,b,c,d,e,f构成的列表
    /前面的参数只能按位置传递
    '''
    return [a, b, c, d, e, f]

# func1调用：按位置传递、按参数传递都可以
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, c=2, d=0, e=5, f=3))

# func2调用：d,e,f必须按关键字传递
print(func2(11, 99, c = 22, d = 0, e = 55, f = 33))
print(func2(a = 11, b = 99, c = 22, d = 0, e = 55, f = 33))
#pritn(func2(11, 99, 22, 0, 55, 33))

# func3调用：a,b,c必须按位置传递
print(func3(111, 999, 222, d = 0, e = 555, f = 333))
#print(func3(a=111, b=999, c=222, d=0, e=55, f=33) )

 

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task2_2

实验源码

list1 = [1, 9, 8, 4]

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

 

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 答：是。

 

task2_3

实验源码

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

# 补足一行代码，调用func()并打印生成的列表，使得结果为[1,2,3,4,5,6]
print(func(1, 2, 3, e=5, d=4, f=6))

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task3

实验源码

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 = abs(delta ** 0.5)
    p1 = -b / a / 2
    p2 = delta_sqrt / a / 2

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

    return root1, root2


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('有其他错误发生\n')
    else:
        root1, root2 = solve(a, b, c)
        print(f'root1 = {root1:.2f}, root2 = {root2:.2f}')
        print()

 

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补加代码后

实验源码

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 = abs(delta ** 0.5)
    p1 = -b / a / 2
    p2 = delta_sqrt / a / 2

    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('有其他错误发生\n')
    else:
        root1, root2 = solve(a, b, c)
        print(f'root1 = {root1:.2f}, root2 = {root2:.2f}')
        print()

 

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task4

实验源码

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

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

 

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task5

实验源码

def is_prime(n):
    if n == 1:
        return False
    t = int(pow(n, 0.5))
    while t > 1:
        if n % t == 0:
            return False
        t -= 1
    else:
        return True


primes = []
for i in range(21):
    if is_prime(i):
        primes.append(i)

for o in range(3, 21):
    if o % 2 == 0:
        for prime in primes:
            ans = o - prime
            if ans in primes:
                print(f'{o} = {prime} + {ans}')
                break

 

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task6

实验源码

# def encoder(n):
#     ans = ''
#     for i in n:
#         if i.isalpha():
#             ans += chr((ord(i)+5-97) % 26 + 97)
#         else:
#             ans += i
#     return ans
#
#
# def decoder(n):
#     ans = ''
#     for i in n:
#         if i.isalpha():
#             ans += chr((ord(i)-5-97) % 26 + 97)
#         else:
#             ans += i
#     return ans

s = 'abcdefghijklmnopqrstuvwxyz'


def encoder(n):
    ans = ''
    for i in n:
        if i.istitle():
            s1 = s.upper()
            tip1 = s1.index(i)
            ans += s1[(tip1 + 5) % 26]
        elif i.isalpha():
            tip2 = s.index(i)
            ans += s[(tip2 + 5) % 26]
        else:
            ans += i
    return ans


def decoder(n):
    ans = ''
    for i in n:
        if i.istitle():
            s1 = s.upper()
            tip1 = s1.index(i)
            ans += s1[(tip1 - 5) % 26]
        elif i.isalpha():
            tip2 = s.index(i)
            ans += s[(tip2 - 5) % 26]
        else:
            ans += i
    return ans


#主体代码逻辑
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)

 

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task7

实验源码

def collatz(n):
    lst = [n]
    while n != 1:
        if n % 2 == 0:
            n /= 2
            lst.append(n)
        else:
            n = n * 3 + 1
            lst.append(n)
    return lst


try:
    x = input('输入一个正整数：')
    if x.isdigit() == False or int(x) <= 0:
        raise ValueError('must be a positive integer')
except ValueError as e:
    print(repr(e))
    print()
else:
    ans = collatz(int(x))
    print(ans)

 

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task8

实验源码

def func(n):
    if n == 1:
        return 1
    else:
        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 = {n}, ans = {ans}')

 

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