实验4 函数与异常处理编程

发布时间 2023-05-23 17:24:36作者: 杨星雨

task1

源代码:

print(sum)
sum = 42
print(sum)

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

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

  运行结果:

答:不是,line1:内置作用域,line3和line11:全局作用域,line7:局部作用域。

task2_1

源代码:

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) )

  运行结果:

 

task2_2

源代码:

list1 = [1, 9, 8, 4]

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

  运行结果:

答:必须使用。

task2_3

源代码:

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))

  

运行结果:

 

task3

源代码:

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/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


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()

  运行结果:

函数solve()的说明信息被打印

task4

源代码:

def list_generator(x,y,s=1):
    lis=[]
    while x<=y:
        lis.append(x)
        x=x+s
    return lis



list1 = list_generator(-5, 5)
print(list1)

list2 = list_generator(-5, 5, 2)
print(list2)

list3 = list_generator(1, 5, 0.5)
print(list3)

  

运行结果:

 

task5

源代码:

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

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

  

运行结果:

 

task6

源代码:

# 编码函数encoder()定义
def encoder(a):
    c = ''
    for i in a:
        if i.isalpha():
            temp = ord(i)+5
            if chr(temp).isalpha():
                c += chr(temp)
            else:
                c += chr(temp-26)
        else:
            c += i
    return c

# 解码函数decoder()定义
def decoder(x):
    z = ''
    for i in x:
        if i.isalpha():
            temp = ord(i)-5
            if chr(temp).isalpha():
                z+=chr(temp)
            else:
                z+=chr(temp+26)
        else:
            z += i
    return z

# 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)

  

运行结果:

 

task7

源代码:

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

try:
    x = int(input('Enter a positive integer:'))
    if x <= 0:
        raise
except:
    print('Error:must be a positive integer')
else:
    print(collatz(x))

  

运行结果:

 

task8

源代码:

# 函数func()定义
def func(n):
    result = 1
    for i in range(n):
        result *= 2
    return result-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}')

  

运行结果: