# 实验四

print(sum)
sum = 42
print(sum)

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

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

实践任务2.2:

list1 = [1, 9, 8, 4]

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

实践任务2.3:

def func(a, b, c, /, *, d, e, f):
return( [a,b,c,d,e,f] )

print(func(1,2,3,d=5,e=6,f=7))

实践任务3：

def solve(a,b,c):
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

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()

实验任务4：

def list_generator(begin,end,step=1):
x = []
i = begin
while i >= begin and i<= end:
x.append(i)
i += step
return x

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

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

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

实践任务5：

def is_prime(n):
if n < 2:
return False
for i in range(2,int(n**0.5)+1):
if n % i == 0:
return False
return True

h=[i for i in range(21)]
for x in h[::2]:
for a in range(0,21):
if is_prime(a) is True:
if is_prime(x-a) is True:
print(f'{x}={a}+{x-a}')
break
else:
a=1+a
else:
a=1+a

实践任务6：

def encoder(strs):
a=list(strs)
i=0
while i <len(strs):
b = ord(a[i])
if 65<=b<=85 or 97<=b<=117:
c=chr(b+5)

elif 85<=b<=90 or 117<=b<=122:
c=chr(b-21)
else:
c=chr(b)
a[i]=c
i+=1
return ''.join(a)

def decoder(strs):
a = list(strs)
i=0
while i < len(strs):
b = ord(a[i])
if 70<=b<=90 or 102<=b<=122:
c=chr(b-5)
elif 65<=b<=70 or 97<=b<=102:
c=chr(b+21)
else:
c=chr(b)
a[i] = c
i+=1
return ''.join(a)

a=input('输入英文文本: ')
print(f'编码后的文本:{encoder(a)}')
print(f'对编码后的文本解码:{decoder(encoder(a))}')

实践任务7：

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

posted @ 2022-05-10 23:03  天天三顿  阅读(2)  评论(1编辑  收藏  举报