python 异常处理，打开文件

#python 异常测试
try:
    a = "异常测试"
    print(aa)
#打印所有异常
except BaseException as msg: 
    print(msg)
#没有异常时执行else
else:
    print("没有异常")

不管是否出现异常，finally 都会被执行

try:
    print(aa)
except Exception as e:
    print(e)
finally:
    print("不管是否异常，都会执行")

python 无自增运算符，处理自增 i = i + 1

def main():
    i = 0
    with open("常用字典.txt", 'r') as f:
        while(1):
            if f.readline():
                print(f.readline().strip())
                i = i + 1
                print(i)
            else:
                print('读取结束')
                break
#这样执行的结果只会是打印出一半的文件，每一次 readline() 调用指针都会向下移

这样就行了

def main():
    i = 0
    with open("常用字典.txt", 'r') as f:
        while(1):
            strs = f.readline().strip()
            if strs:
                i = i + 1
                print(i)
                print(strs)
            else:
                print('读取结束')
                break