实验四 函数与异常处理应用编程

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#test1.py
print(sum)
sum = 42
print(sum)

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

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

不是一个变量名。

line1   42

line3 and line7    n+1

line11    7+1+7+1=16

#test2.py
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) )

line33：

line38：

#test2_2.py
list1 = [1, 9, 8, 4]

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

否

#test2_3.py
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))

 

#test_3.py
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: int 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:
        a,b,c = eval(input('Enter eqution coefficient: '))
        if a == 0:
            raise
    except:
        print('invalid input, or, a is zero')
        break
    else:
        root1, root2 = solve(a, b, c)
        print(f'root1 = {root1:.2f}, root2 = {root2:.2f}')
        print()

 

#test_4.py
def list_generator(a,b,c=1):
    y = []
    while a <= b:
        y.append(a)
        a+=c
    return y

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

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

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

 

#test.5py
def isPrime(x):
    i=2
    while i<=x-1 and x%i!=0:
        i=i+1
    if i==x:
        return True
    else:
        return False
for j in range(4,21,2):
    for n in range(2,j):
        if isPrime(n) and isPrime(j-n):
            print(f'{j}={n}+{j-n}')
            break

#test_6.py
def encoder(x):
    a=5
    b=''
    for i in x:
        if 65<=ord(i)<=85:
            b+=chr(ord(i)+5)
        elif 97<=ord(i)<=117:
            b+=chr(ord(i)+5)
        elif 85<ord(i)<=90:
            b+=chr(65+(a-(90-ord(i))))
        elif 117<ord(i)<=122:
            b+=chr(97+(a-(122-ord(i))))
        else:
            b+=i
    return b
def decoder(y):
    c=5
    d=''
    for j in y:
        if 70<=ord(j)<=90:
            d+=chr(ord(j)-5)
        elif 102<=ord(j)<=122:
            d+=chr(ord(j)-5)
        elif 65<=ord(j)<70:
            d+=chr(90-(c-(ord(j)-65)))
        elif 97<=ord(j)<102:
            d+=chr(122-(c-(ord(j)-97)))
        else:
            d+=j
    return d
x=input('输入英语文本:')
print('编码后的文本:',encoder(x))
print('对编码后的文本解码:',decoder(encoder(x)))

#test_7.py
def collatz(n):
    if n%2==0:
        n=n/2
    else:
        n=3*n+1
    return int(n)
try:
    n=eval(input('Enter a positive integer:'))
    if n<=0 or type(n)!=int:
        raise
except:
    print('Error: must be a positive integer')
else:
    list=[]
    while n!=1:
        list.append(n)
        n=collatz(n)
    list.append(n)
    print(list)

 

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