pandas合并数据表格

两列数据判断，有为空的则两列合并，不为空的去重，最后合并在一列
或者是如何拼接两个表格重复的列名那些列只保存不为空的内容作为一列即可

是要这样的效果？

import pandas as pd
from random import randint

def func1(x1,x2):
    if pd.isnull(x1):
        return x2
    return x1
lst = [ [randint(1,100),  randint(1,100) ] for m in range(11)]
for i in range(len(lst)):
     lst[i][randint(0,1)] = None
df1 = pd.DataFrame(lst,columns=['H1','H2'])
print(df1)

df1['H3'] = df1.apply(lambda x: func1(x['H1'], x['H2']), axis=1)
print(df1)