统计每行的yes的个数
isA=c("yes","no","yes",NA)
isB=c("no","yes","no",NA)
df <- data.frame(isA,isB)
df
isA isB
1 yes no
2 no yes
3 yes no
4 <NA> <NA>
df$ans<-apply(df,1,function(x) table(x)["yes"])
df
isA isB ans
1 yes no 1
2 no yes 1
3 yes no 1
4 <NA> <NA> NA
REF
https://bbs.pinggu.org/thread-3978012-1-1.html
https://bbs.pinggu.org/forum.php?mod=viewthread&tid=6875101&page=1
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dataframe某列满足特定值的数量
1. df[df["val"]==0].id.count()
2. len(df[df["val"]==0])
REF
https://blog.csdn.net/qq_41973062/article/details/111224007
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原文：https://www.cnblogs.com/emanlee/p/14878523.html