实验四

task1

line1 B68ZZZ33344uilt-in 

line3Global

line7Local

line11Enclosing

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))

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))

task3

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


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()

task4

def list_generator(a,b,c=1):
    t=[]
    if type(c)==int:
       for i in range(a-1,b,c):
           t.append(i)
    else:
        j=a
        while j<=b:
            t.append(j)
            j=j+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

import math
def is_prime(m):
    result = True
    if m <= 1:
        if True:
            result = False
        for i in range(2, int(math.sqrt(m) + 1)):
            if m % i == 0:
                result = False
    elif m > 1:
        if m == 2:
            result = True
        elif m % 2 == 0:
            result = False
        elif m > 2:
            a = int(math.sqrt(m)) + 1
            for j in range(3, a, 2):
                if m % j == 0:
                    result = False
        else:
            result = True
    else:
        result = False
    return result
t=[]
for i in range(1,21):
    if is_prime(i)==True:
        t.append(i)
    else:
        continue
print(t)
for i in t:
    for j in t:
        if ((i + j)%2==0)and((i+j)<=20):
            print(f'{i+j}={i}+{j}')

def encoder(m):
    t=[]
    for i in m:
        j=ord(i)
        if (65<=j<=85)or(97<=j<=117):
           j = j+5
        elif(86<=j<=90)or(118<=j<=122):
            j=j+5-26
        else:
            j=j
        i = chr(j)
        t.append(i)
    n=''.join(t)
    return n
def decoder(m):
    t1=[]
    for i in m:
        j=ord(i)
        if (122>=j >=102)or(90>=j>=70):
            j = j-5
        elif(101>=j>=97)or(69>=j>=65):
            j = j-5+26
        else:
            j=j
        i =chr(j)
        t1.append(i)
    n = ''.join(t1)
    return n
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(i):
    t=[i]
    while i!=1:
         if i%2==0:
            i=i/2
            t.append(int(i))
         elif i%2==1:
            i=i*3+1
            t.append(int(i))
    return t
try:
    i=int(input('Enter a positive integer:'))
    if i<=0:
        raise ValueError
except ValueError:
    print('Error:must be a positive integer')
else:
    print(collatz(i))

task8

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