解决Python报错:local variable 'xxx' referenced before assignment
来源:互联网 发布:信息融合数据关联 编辑:程序博客网 时间:2024/05/16 17:22
在外面定义了一个变量 xxx ,然后在python的一个函数里面引用这个变量,并改变它的值,结果报错local variable 'xxx' referenced before assignment,代码如下:
view plaincopy to clipboardprint?
- xxx
= 23 - def
PrintFileName(strFileName): -
if xxx 23:== -
print strFileName -
xxx = 24 -
- PrintFileName("file")
错误的意思就是xxx这个变量在引用前还没有定义,这上面不是定义了么?但是后来我把xxx = 24这句去掉之后,又没问题了,后来想起python中有个global关键字是用来引用全局变量的,尝试了一下,果然可以了:
view plaincopy to clipboardprint?
- xxx
= 23 - def
PrintFileName(strFileName): -
global xxx -
if xxx 23:== -
print strFileName -
xxx = 24 -
- PrintFileName("file")
原来在python的函数中和全局同名的变量,如果你有修改变量的值就会变成局部变量,在修改之前对该变量的引用自然就会出现没定义这样的错误了,如果确定要引用全局变量,并且要对它修改,必须加上global关键字。
0 0
- 解决Python报错:local variable 'xxx' referenced before assignment
- 解决Python报错:local variable 'xxx' referenced before assignment(引)
- python 报错 :local variable 'totalCount' referenced before assignment
- python报错:local variable 'xxxx' referenced before assignment
- python的UnboundLocalError: local variable 'xxx' referenced before assignment
- python的UnboundLocalError: local variable 'xxx' referenced before assignment
- Python的UnboundLocalError: local variable 'xxx' referenced before assignment
- python出错:local variable XXX referenced before assignment
- Python进阶(三十二)-local variable 'xxx' referenced before assignment
- Python的UnboundLocalError: local variable 'xxx' referenced before assignment
- local variable 'xxx' referenced before assignment
- local variable 'xxx' referenced before assignment
- local variable 'xxx' referenced before assignment
- local variable 'xxx' referenced before assignment
- local variable 'xxx' referenced before assignment
- UnboundLocalError: local variable 'XXX' referenced before assignment
- local variable XXX referenced before assignment
- local variable 'xxx' referenced before assignment
- Android开发坑之Jpush篇
- Visual C++ 6.0 实训教程
- Linux操作系统
- 欢迎使用CSDN-markdown编辑器
- java工厂模式详解
- 解决Python报错:local variable 'xxx' referenced before assignment
- Linux基础教程
- 信息安全技术实用教程
- 单片机原理与应用技术
- 云舒网络译:Rancher1.0正式版发布
- C++11的Lambda
- C语言程序设计教程
- RHCE考试经验
- 红帽 Linux 考试 要求