python中else的用法

 for+else    

def else1(num):
    for i in range(num):
        if(i>10):
            break
        print(i)
    else:
        print("over") #当for循环正常结束时，会执行该条语句


else1(5)
print("##"*20)
else1(20)

结果：

0
1
2
3
4
over
########################################
0
1
2
3
4
5
6
7
8
9
10

while+else

def else2(num):
    while num > 0:
        if(num==10):
            break
        num-=1
        print(num)
    else:
        print("over") #当while循环正常结束时，会执行该条语句


else2(5)
print("##"*20)
else2(20)

结果：
4
3
2
1
0
over
########################################
19
18
17
16
15
14
13
12
11
10

try+else

def ex(num):
    if(num==10):
        raise BaseException("BaseException!")

def else3(num):
    try:
        for i in range(num):
            ex(i)
            print(i)
    except BaseException as msg:
        print(msg)
    else:
        print("over")
    finally:
        print("end")

else3(5)
print("##"*20)
else3(20)

结果：
0
1
2
3
4
over
end
########################################
0
1
2
3
4
5
6
7
8
9
BaseException!
end