tep_extending_pandas_blog1_5.py

class SpanOpMixin:
  def __add__(self, other) -> Union["Span", "SpanArray"]:
 
    if isinstance(other, (ABCDataFrame, ABCSeries, ABCIndexClass)):
      # Rely on pandas to unbox and dispatch to us.
      return NotImplemented

    if isinstance(self, Span) and isinstance(other, Span):
      # Span + *Span = Span
      return Span(self.target_text,
                  min(self.begin, other.begin),                 
                  max(self.end, other.end))
 
    # SpanArray + *Span* = SpanArray
    return SpanArray(self.target_text, 
                     np.minimum(self.begin, other.begin), 
                     np.maximum(self.end, other.end))