为什么我们需要删除get dummy函数中的第一个参数

Question

我有一个关于get dummy函数的问题。为什么我们需要drop_first=true或false而得到虚拟。使用此参数的目的是什么？你知道吗

我正在接受逻辑回归的警告。这是'线搜索算法没有收敛'。这个警告和drop_first=false参数之间有关系吗？你知道吗

警告完全在下面

C:\Users\aslii\lib\site-packages\scipy\optimize\linesearch.py:313: LineSearchWarning: The line search algorithm did not converge
  warn('The line search algorithm did not converge', LineSearchWarning)
C:\Users\aslii\lib\site-packages\sklearn\utils\optimize.py:195: UserWarning: Line Search failed
  warnings.warn('Line Search failed')
C:\Users\aslii\lib\site-packages\scipy\optimize\linesearch.py:313: LineSearchWarning: The line search algorithm did not converge
  warn('The line search algorithm did not converge', LineSearchWarning)
C:\Users\aslii\lib\site-packages\sklearn\utils\optimize.py:195: UserWarning: Line Search failed
  warnings.warn('Line Search failed') 

提前谢谢