python: if __name__
最近一直在学习用python,因为遇到过几次 if __name__ == "__main__" 表达式,当时没当作回事,其实这个作用挺大的,因此写下来记录一下备忘。
python的语法我就不在此描述了,因为相关文档很多。
test.py
def test():
print "test is running"
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
if __name__ == "__main__":#自运行时调用该程序块
print "test main is working"
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
if __name__ == "test":#import时调用该程序块
print "test is invoked"
自执行效果如图:
![](https://images.cnblogs.com/cnblogs_com/jansen2008/python_test.JPG)
import执行效果如图:
![](https://images.cnblogs.com/cnblogs_com/jansen2008/python_test1.JPG)
执行test()方法效果如图:
![](https://images.cnblogs.com/cnblogs_com/jansen2008/python_test0.JPG)
通过这个例子,python应用模块的自测试程序都放在 if __name__ == "__main__" 条件块下是多么方便。
python的语法我就不在此描述了,因为相关文档很多。
test.py
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
![](https://www.cnblogs.com/Images/OutliningIndicators/None.gif)
自执行效果如图:
import执行效果如图:
执行test()方法效果如图:
通过这个例子,python应用模块的自测试程序都放在 if __name__ == "__main__" 条件块下是多么方便。