for-else loop

It is mainly used to judge whether the cycle is incomplete （ That is, whether it is interrupted in the middle ）, If the cycle runs completely （ Not interrupted halfway ）, execute else Statement content , Otherwise, do not execute ,
Common ways to jump out of the loop ：break、continue、return（ Within the function ）

for-else The logic of loops in judging prime numbers

If it can be divided （ Not primes ）,break Jump out of the present for loop , Do nothing ; If it's not divisible （ Prime number ）,for After iteration, there are no books break Out of the loop , perform else sentence , Add this prime number to the list

Example

a=[3,1,12,5,14,8,7,2,5,3,2,6,7,2,3,8,5]# Find the primes and sum them 
b=[]
for i in a:
if i>1:
for j in range(2,i//2+1):
if i%j==0:
break
else:
b.append(i)
print(b)
print(sum(b))

Of course, you can also use the method of defining functions

def iszhi(n):
if n>1:
for i in range(2,n//2+1):
if n%i==0:
return False
else:
return True
a=[3,1,12,5,14,8,7,2,5,3,2,6,7,2,3,8,5]
b=[]
for j in a:
if iszhi(j)==True:
b.append(j)
print(b)
print(sum(b))