即使这看起来真的很简单，也让我发疯。为什么.astype（int）不将浮点数更改为int？谢谢
df_new = pd.crosstab(df["date"], df["place"]).reset_index()
places = ['cityA', "cityB", "cityC"]
df_new[places] = df_new[places].fillna(0).astype(int)
sums = df_new.select_dtypes(pd.np.number).sum().rename('total')
df_new = df_new.append(sums)
print(df_new)
输出：
place date cityA cityB cityC
0 2008-01-01 0.0 0.0 51.0
1 2009-06-01 0.0 618.0 0.0
2 2015-07-01 549.0 0.0 0.0
3 2016-01-01 41.0 0.0 0.0
4 2016-04-01 62.0 0.0 0.0
5 2017-01-01 800.0 0.0 0.0
6 2018-07-01 69.0 0.0 0.0
total NaT 1521.0 618.0 51.0