实验四

测试1

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

 第一个 内置作用域

第二个 全局作用域

第三个 局部作用域

第四个 全局作用域

 测试2

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,f=33,e=55) )

print( func3(111, 999, 222, 0, 555, 333))
print( func3(111, 999, 222, d=0, e=555, f=333) )

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

 

 python内置函数sorted()中，参数reverse的传递方式是否必须使用关键字传递？

是

 

 测试三

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()

 

 实验四

def list_generator(a,b,c=1):
    if c>=1:
        list1=[i for i in range(a,b+1)]
        list1=list1[::c]
        return list1
    else:
        list2=[j for j in range(a,b+1)]
        list3=[]
        for s in range(a,b):
            list3.append(s+c)
        list2=list2+list3
        list2=sorted(list2)
        return list2
list1 = list_generator(-5, 5)
print(list1)
list2 = list_generator(-5, 5, 2)
print(list2)
list3 = list_generator(1, 5, 0.5)
print(list3)

 

 测试五

def is_prime(n):
    if n <= 1:
        return False
    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 j in range(2,i):
        t=i-j
        if is_prime(t) and is_prime(j) and j<=t and j!=t:
            print(j,'+',t,'=',i)

 测试6

def encoder(n):
    list=[]
    for i in n:
        i=ord(i)
        if 97<=i<=117 or 65<=i<=85:
            i=i+5
        elif 117<i<=122 or 85<i<=90:
            i=i-21
        else:
            i=i
        list.append(chr(i))
    return ''.join(list)
def decoder(n):
    n=encoder(n)
    list = []
    for i in n:
        i = ord(i)
        if 102<=i<=122 or 70<=i<=90:
            i=i-5
        elif 97<=i<102 or 65<=i<70:
            i=i+21
        else:
            i = i
        list.append(chr(i))
    return ''.join(list)
n = input('输入英文文本：')
print('编码后'+encoder(n))
print('编码后'+decoder(n))

 

 测试7

 

def collatz(n):
    list = [n]
    while list[-1]!= 1:
        if  list[-1] % 2==0:
            list.append(int(list[-1]/2))
        else:
            list.append(int(list[-1]*3+1))
    return list
try:
    n = eval(input('输入一个整数'))
    print(collatz(n))
except:
    print('must be a positive integer')