divident.append(hasThisYearDivident)
noHasThisYearDivident = divident.drop_duplicates(subset='ts_code', keep=False, inplace=True, ignore_index=True)

> a=set((1,2,3))
> a
{1, 2, 3}
> b=set((2,3,4))
> b
{2, 3, 4}
> a-b
{1}

> import pandas as pd
> data_a={'state':[1,1,2],'pop':['a','b','c']}
> data_b={'state':[1,2,3],'pop':['b','c','d']}
> a=pd.DataFrame(data_a)
> b=pd.DataFrame(data_b)
> a
  state pop
0   1  a
1   1  b
2   2  c
> b
  state pop
0   1  b
1   2  c
2   3  d
> a=a.append(b)
> a=a.append(b)
> a
  state pop
0   1  a
1   1  b
2   2  c
0   1  b
1   2  c
2   3  d
0   1  b
1   2  c
2   3  d
> a.drop_duplicates(subset=['state','pop'],keep=False)
  state pop
0   1  a