CODEWITHSUNDEEP
r
user3833190
user3833190

Reputation:

How to find & remove duplicates in data frames?

I have the follwing data frame which happens to be NBA draft data:

 draft_year draft_round teamid playerid draft_from
 1961           1         Bos    Pol1      Nan
 2001           1         LA     Ben2      Cal
 1967           2         Min    Mac2      Nan
 2001           1         LA     Ben2      Cal
 2000           1         C      Sio1      Bud
 2000           1         C      Gio1      Bud

I would like to find & remove only those rows with duplicates in playerid. For obvious reasons, the remaining duplicates have a meaningful purpose and must be kept.

Upvotes: 3

Views: 166

Answers (3)

akrun
akrun

Reputation: 887851

You could also use dplyr

library(dplyr)
 unique(df, group_by="playerid")
 #  draft_year draft_round teamid playerid draft_from
 #1       1961           1    Bos     Pol1        Nan
 #2       2001           1     LA     Ben2        Cal
 #3       1967           2    Min     Mac2        Nan
 #5       2000           1      C     Sio1        Bud
 #6       2000           1      C     Gio1        Bud

Or

 df %>%
 group_by(playerid) %>%
 filter(row_number()==1)

Upvotes: 2

RP-
RP-

Reputation: 5837

You can achieve this by using duplicated or unique()

new_df <- df[!duplicated( df$playerid), ]

Upvotes: 2

David Arenburg
David Arenburg

Reputation: 92300

In data.table package you have a by parameter in the unique function

library(data.table)
unique(setDT(df), by = "playerid")
#    draft_year draft_round teamid playerid draft_from
# 1:       1961           1    Bos     Pol1        Nan
# 2:       2001           1     LA     Ben2        Cal
# 3:       1967           2    Min     Mac2        Nan
# 4:       2000           1      C     Sio1        Bud
# 5:       2000           1      C     Gio1        Bud

Upvotes: 2

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