分组后如何针对大熊猫的情况

Question

我正在学习如何使用Pandas，但我找不到解决问题的方法。我只想通过分组">occurred_on"来选择">导致地震"=">的行。我在下面有我的代码：

total_Earthquakes_PerYear = df.
groupby(df['occurred_on'].dt.year)
['cause'].value_counts()
total_Earthquake_PerYear

输出：

occurred_on  cause            
1969         earthquake           322
nuclear explosion      1
1970         earthquake           344
nuclear explosion      1
1971         earthquake           386
1972         earthquake           388
1973         earthquake           394
nuclear explosion      6
explosion              1

如何获取">导致"==">地震'的行？

我试着用这个：

total_Earthquakes_PerYear = df[df['cause' == 'earthquake']].groupby(df['occurred_on'].dt.year)['cause'].count()

但仍然一无所获。谢谢

Answer 1

我的评论中的整行是

total_Earthquakes_PerYear = (
df[df['cause'] == 'earthquake']
.groupby(df['occurred_on'].dt.year)
['cause'].value_counts()
)

或者你可以每年都有所有的原因，只过滤地震

total_PerYear = df.
groupby(df['occurred_on'].dt.year)
['cause'].value_counts()
total_Eathquakes_PerYear =  
total_PerYear[total_PerYear.cause == 'earthquake']