在Python中查找每个名称的计数、最早日期和最晚日期
假设我有一个如下的数据,包含名称、类和日期在Python中查找每个名称的计数、最早日期和最晚日期,python,Python,假设我有一个如下的数据,包含名称、类和日期 Name class Date A 7th grade 1/1/2016 A 7th grade 1/2/2016 A 7th grade 1/3/2016 A 7th grade 1/4/2016 A 7th grade 1/5/2016 A 7th grade 1/6/2016 A 7th grade 1/7/2016 B 8th grade 1/8/2016 B 8th
Name class Date
A 7th grade 1/1/2016
A 7th grade 1/2/2016
A 7th grade 1/3/2016
A 7th grade 1/4/2016
A 7th grade 1/5/2016
A 7th grade 1/6/2016
A 7th grade 1/7/2016
B 8th grade 1/8/2016
B 8th grade 1/9/2016
B 8th grade 1/10/2016
C 9th grade 1/11/2016
C 9th grade 1/12/2016
C 9th grade 1/13/2016
C 9th grade 1/14/2016
C 9th grade 1/15/2016
C 9th grade 1/16/2016
C 9th grade 1/17/2016
C 9th grade 1/18/2016
C 9th grade 1/19/2016
C 9th grade 1/20/2016
C 9th grade 1/21/2016
C 9th grade 1/22/2016
我正在寻找一个输出,这将给我的每个名字的值计数,他们各自的等级和最早的日期和最新的日期。我的输出是
Name grade count earlydate latestdate
A 7thgrade 7 1/1/2016 1/7/2016
B 8th grade 3 1/8/2016 1/10/2016
C 9th grade 12 1/11/2016 1/22/2016
我可以通过
data.groupby('name','grade').count()
or
data.groupby('name','grade').size()
但无法在“日期”列中找到“最早日期”和“最晚日期”
有人能帮我吗?
可能是这样的:
data.groupby('name','grade').agg({'date' : [np.min, np.max]}).count()
您使用的是哪种数据库?尝试使用联接,sqlI中的MIN/MAX函数将其作为python数据帧。你需要在家里做这件事吗python@clemkoa谢谢你的链接。但在该链接中,日期作为索引而不是列,也不会返回我想要的结果。我想要一个数据框,它会给出这些细节,比如shownok,那么也许?