函数与异常处理应用编程

task1
print(sum)
sum = 42
print(sum)
def inc(n):
  sum = n+1
  print(sum)
  return sum
sum = inc(7) + inc(7)
print(sum)

　　

不是一个变量名

line1 内置

line3 全局作用域

line7 局部作用域

line11 全局作用域

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
    /前面的的参数只能按位置传递
    '''
    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))

　　

 

 task2-2

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

 

 必须关键词传递

 

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: 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 ZeroDivisionError
    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()

　　

　　

 

 

 

def list_generator(a,b,c=1):
    l=[a]
    while True:
        if c==None:
            a+=1
            l.append(a)
            if a==b:
                break
        else:
            a+=c
            l.append(a)
            if a==b:
                break
    return l
list1 = list_generator(-5,5)
print(list1)
 
list2 = list_generator(-5,5,2)
print(list2)
 
list3 = list_generator(1,5,0.5)
print(list3)

　

 

 

from math import sqrt
 
def is_prime(n):
    if n==1 or n==0:
        return False
    for i in range(2,int(sqrt(n)+1)):
        if n%i==0:
            return False
    return True
def gd(x):
    for i in range(2,x):
        if is_prime(i):
            if is_prime(x-i):
                print(x,'=',i,'+',x-i)
                return True
    return False
i=4
while(gd(i) and i<20):
    i+=2

　

 

 

def encoder(s):
    s=list(s)
    for i in range(len(s)):
        if s[i].isalpha():
            if 'a'<=s[i].lower()<'v':
                s[i]=chr(ord(s[i])+5)
            else:
                s[i]=chr(ord(s[i])-21)
        else:
            s[i]=s[i]
    s=''.join(s)
    return s
def decoder(s):
    s=list(s)
    for i in range(len(s)):
        if s[i].isalpha():
            if 'a'<=s[i].lower()<='e':
                s[i]=chr(ord(s[i])+21)
            elif 'e'<s[i].lower()<='z':
                s[i]=chr(ord(s[i])-5)
        else:
            s[i]=s[i]
    s=''.join(s)
    return s
s=input('输入英文文本: ')
print(f'编码后的文本:{encoder(s)}')
print(f'对编码后的文本解码:{decoder(encoder(s))}')

　

 

 

def collatz(n):
    if n%2==0:
        return int(n/2)
    else:
        return int(n*3+1)
try:
    l=[]
    x=int(input('Enter a positive integer: '))
    l.append(x)
    if x<=0:
        raise
    while True:
        c=collatz(x)
        l.append(c)
        x=c
        if x==1:
            break
    print(l)
except:
    print('Error: must be a positive integer')