Keep only non-duplicate rows based on a Column Value [duplicate]

Question

This question already has an answer here:

• How can I remove all duplicates so that NONE are left in a data frame? 2 answers

This is follow up to a previous question.

The dataset looks like the following:

dat <- read.table(header=TRUE, text="
                 ID  Veh oct nov dec jan feb
1120    1   7   47  152 259 140
2000    1   5   88  236 251 145
2000    2   14  72  263 331 147
1133    1   6   71  207 290 242
2000    3   7   47  152 259 140
2002    1   5   88  236 251 145
2006    1   14  72  263 331 147
2002    2   6   71  207 290 242
")

dat

    ID Veh oct nov dec jan feb
1 1120   1   7  47 152 259 140
2 2000   1   5  88 236 251 145
3 2000   2  14  72 263 331 147
4 1133   1   6  71 207 290 242
5 2000   3   7  47 152 259 140
6 2002   1   5  88 236 251 145
7 2006   1  14  72 263 331 147
8 2002   2   6  71 207 290 242

I like to keep only non-duplicate rows based on first column values. The output will be like this:

    ID Veh oct nov dec jan feb
1 1120   1   7  47 152 259 140
2 1133   1   6  71 207 290 242
3 2006   1  14  72 263 331 147

A possible solution is here. But that question doesn't have reproducible example.

Answer 1

We can use duplicated

dat[!(duplicated(dat$ID)|duplicated(dat$ID, fromLast = TRUE)),]