python - Pandas - 计数项目

Question

我需要将此信息传递到图表中，我需要每个月与数量进行比较。

    year    state   month   number  date
718 1998    Amazonas    Janeiro 0.0     1998-01-01
719 1999    Amazonas    Janeiro 3.0     1999-01-01
720 2000    Amazonas    Janeiro 7.0     2000-01-01
721 2001    Amazonas    Janeiro 3.0     2001-01-01
722 2002    Amazonas    Janeiro 17.0    2002-01-01
723 2003    Amazonas    Janeiro 158.0   2003-01-01
724 2004    Amazonas    Janeiro 123.0   2004-01-01
725 2005    Amazonas    Janeiro 44.0    2005-01-01
726 2006    Amazonas    Janeiro 20.0    2006-01-01
727 2007    Amazonas    Janeiro 37.0    2007-01-01
728 2008    Amazonas    Janeiro 16.0    2008-01-01
729 2009    Amazonas    Janeiro 9.0     2009-01-01
730 2010    Amazonas    Janeiro 82.0    2010-01-01
731 2011    Amazonas    Janeiro 53.0    2011-01-01
732 2012    Amazonas    Janeiro 6.0     2012-01-01
733 2013    Amazonas    Janeiro 37.0    2013-01-01
734 2014    Amazonas    Janeiro 46.0    2014-01-01
735 2015    Amazonas    Janeiro 35.0    2015-01-01
736 2016    Amazonas    Janeiro 770.0   2016-01-01
737 2017    Amazonas    Janeiro 65.0    2017-01-01

我有一个数据集，我需要对所有数据进行求和，例如，一月 = 5000，二月 = 6790

我尝试了 sum() 和 count()，但没有成功。

dt['month'].sum()

和

dt['month'].count()

Answer 1

您需要首先使用 groupby 函数对数据框进行分组:

例如:

dt.groupby('month')['number'].sum()

您之前执行此操作的方式只是对列进行求和，而不管其值如何。