实验4 函数与异常处理编程

task1

print(sum)
sum = 42
print(sum)
def inc(n):
    sum = n+1
    print(sum)
    return sum
sum = inc(7) + inc(7)
print(sum)

答案：不是。line1为内置作用域，line3和line11为全局作用域，line7为局部作用域。

task2-1

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, 2, f=3, d=0, e=5))

# func2调用：d,e,f必须按关键字传递
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))

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

task2-2

list1 = [1, 9, 8, 4]
print( sorted(list1) )
print( sorted(list1, reverse=True) )
print( sorted(list1, True) )

答案：是。

task2-3

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))

task4

def list_generator(a,b,c=1):
    t = []
    i = a
    while i <= b:
        t.append(i)
        i += c
    return t

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

task5

def is_prime(n):
    i = 2
    while i < n:
        if n % i == 0:
            break
        i += 1
    return i == n
lst = []
for t in range(2,21):
    if is_prime(t) == True:
        lst.append(t)
k = 0
while k <= 20:
    a = 2
    while a <= 20:
        b = 2
        while b <= 20:
            if a in lst and b in lst and a + b == k and k%2 ==0 and a <= b:
                print(k,'=',a,'+',b)
                k += 1
            b += 1
        a += 1
    k += 1

task6

def encoder(text):
    lst = list(text)
    text1 = []
    for i in lst:
        if ord(i) in range(97,97+26) or ord(i.lower()) in range(97,97+26):
            if 'a' <= i <= 'u' or 'A' <= i <= 'U':
                t = chr(ord(i) + 5)
                text1.append(t)
            elif 'v' <= i <= 'z' or 'V' <= i <= 'Z':
                t = chr(ord(i) + 5 - 26)
                text1.append(t)
        else:
            text1.append(i)
        text = ''.join(text1)
    return text
def decoder(text):
    lst1 = list(text)
    text2 = []
    for k in lst1:
        if ord(k) in range(97,97+26) or ord(k.lower()) in range(97,97+26):
            if 'a' <= k <= 'e' or 'A' <= k <= 'E':
                t = chr(ord(k) - 5 + 26)
                text2.append(t)
            elif 'f' <= k <= 'z' or 'F' <= k <= 'Z':
                t = chr(ord(k) - 5)
                text2.append(t)
        else:
            text2.append(k)
        text = ''.join(text2)
    return text

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)

task7

def collatz(n):
    if n.isdigit() and int(n) > 0:
        n1 = int(n)
        lst = [n1]
        while n1 != 1:
            if n1%2 == 0:
                n1 = n1/2
                lst.append(int(n1))
            else:
                n1 = n1*3 + 1
                lst.append(int(n1))
        return lst
    else:
        return 'Error: must be a positive integer'



n = input('Enter a positive integer:')
x = collatz(n)
print(x)

task8

def func(n):
    if n == 1:
        return 1
    elif n > 1:
        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}')