Python 中的错误:未定义名称“df” 我是python 的新手,在 stackoverflow 中用谷歌搜索和搜索了很多小时。但是我的代码仍然有问题。我需要在时间间隔内运行foo函数,并填充数据帧(例如,每秒向 df 添加时间戳)。我仍然遇到错误消息:NameError:name ‘df’ is not defined 谢谢您的回答。 代码: WAIT_TIME_SECONDS =...
File "", line 1, in NameError: name 'a' is not defined 1. 2. 3. 4. 解决方案: 先要给a赋值。才能使用它。在实际编写代码过程中,报NameError错误时,查看该变量是否赋值,或者是否有大小写不一致错误,或者说不小心将变量名写错了。 注:在Python中,无需显示变量声明语句,变量在第一次被赋值时自动声明。
When iterating over an object such as a list, dictionary, or file, enumerate is a useful function. The function returns a tuple containing both the values obtained from iterating over the object, and the loop counter (from the start position of 0). The loop counter is especially handy whe...
def test_number_is_already_defined_in_the_sequence_for_an_already_created_one(self): """testing if a ValueError will be raised when the number is already defined for a Shot in the same Sequence instance """ self.kwargs["number"] = 101 new_shot1 = Shot(**self.kwargs) new_shot1....