CODEWITHSUNDEEP
r
SB77
SB77

Reputation: 87

count rows split by type for many csv files R

I have many csv files and I need to count the number of rows split by type. An example csv format is 

Type,speed
Turtle,10
Lion,50
Cheetah,100
Turtle,12
Lion,70
Cheetah,110
Cheetah,170

So the example output would be:

Type count
turtle 2
lion 2
cheetah 3

I can do this for an individual file using the below R code:

library(dplyr)
##
a1 <- read.csv("data1.csv")
a1 %>% 
  group_by(Type, Type) %>% 
  summarise(count=n())

Can someone help me loop this across all csv files? I have data1.csv to data100.csv.

Upvotes: 2

Views: 220

Answers (1)

talat
talat

Reputation: 70336

As mentioned in the comments you can use list.files to get a list of the files in your directory:

file_list <- list.files(directory) # pattern omitted since they're the only files

Then read all files into a list:

files <- lapply(file_list, read.csv, header=TRUE)
names(files) <- sub("\\.csv$", "", file_list)

Now, you could do:

res <- lapply(files, function(dat) dplyr::count(dat, Type))

Upvotes: 3

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