# 第四次实验

print(sum)
sum=42
print(sum)

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

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

1:内置 2：全局  3：局部  4：全局

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

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))

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
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()

def list_generator(begin,end,model=1):
a=[]
while begin<=end:
a.append(begin)
begin+=model
return a

list1 = list_generator(-5, 5)
print(list1)
list2 = list_generator(-5, 5, 2)
print(list2)
list3 = list_generator(1, 5, 0.5)
print(list3)

def is_prime(n):
if n==1:
return False
elif n==2:
return True
else:
a=2
for i in range(2,n):
if n%i==0:
return False
else:
a+=1
if a==n:
return True

for j in range(2,21,2):
for x in range(1,21):
if is_prime(x)==True and is_prime(j-x)==True and x<=j-x:
print(f'{j}={x}+{j-x}')
break

def encoder(x):
ls=[]
x=list(x)
for i in x:
if 97<=ord(i.lower())<=117:
i=chr(ord(i)+5)
elif 118<=ord(i.lower())<=122:
i=chr(ord(i)-21)
ls.append(i)
return ''.join(ls)

def decoder(x):
ls=[]
x=list(x)
for j in x:
if 102<=ord(j.lower())<=122:
j=chr(ord(j)-5)
elif 97<=ord(j.lower())<=101:
j=chr(ord(j)+21)
ls.append(j)
return ''.join(ls)

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



def collatz(n):
if n%2:
n=3*n+1
else:
n=int(n/2)
return n

n=input('Enter a positive integer:')
try:
n=int(n)
if n<=0:
raise
except:
print('Error:must be a positive integer')
else:
a=[n]
while n!=1:
n=collatz(n)
a.append(n)
print(a)


posted @ 2022-05-10 13:03  张杰的  阅读(6)  评论(3编辑  收藏  举报