学习心得2020.09.06

034 丰富的else语句及简洁的with语句

• 丰富的else语句
  要么怎样，要么不怎样
  干完了能怎样，干不完就别想怎样
  没有问题，那就干吧

求最大约数

def showMaxFactor(num):
    count=num // 2
    while count>1:
        if num%count==0:
            print('%d最大的约数是%d'%(num,count))
            break
        count-=1
    else:
        print('%d是素数！'% num)

num=int(input('请输入一个数：'))
showMaxFactor(num)

try:
    print(int('123'))
except ValueError as reason:
    print('出错啦：'+str(reason))
else:
    print('没有任何异常！')

• 简洁的with语句

try:
    with open('data.txt','w') as f:
        for each_line in f:
            print(each_line)
except OSError as reason:
    print('出错啦：'+ str(reason))