How to Remove First Character from Strings Using dplyr


You can use the following basic syntax in dplyr to remove the first character from each string in a particular column:

library(dplyr)

df_new <- df %>% mutate(across(c('my_column'), substr, 2, nchar(my_column)))

This particular syntax removes the first character from each string in the column called my_column.

Note that we use the substr() function to extract the substring ranging from the second character in each string to the length of the string.

This has the effect of removing the first character from the string.

The following example shows how to use this syntax in practice.

Example: Remove First Character from Strings Using dplyr

Suppose we have the following data frame in R:

#create data frame
df <- data.frame(team=c('XMavs', 'XPacers', 'XHawks', 'XKings', 'XNets', 'XCeltics'),
                 points=c(104, 110, 134, 125, 114, 124))

#view data frame
df

      team points
1    XMavs    104
2  XPacers    110
3   XHawks    134
4   XKings    125
5    XNets    114
6 XCeltics    124

Suppose we would like to remove the first character from each string in the team column.

We can use the following syntax to do so:

library(dplyr)

#remove first character from each string in 'team' column
df_new <- df %>% mutate(across(c('team'), substr, 2, nchar(team)))

#view updated data frame
df_new

     team points
1    Mavs    104
2  Pacers    110
3   Hawks    134
4   Kings    125
5    Nets    114
6 Celtics    124

Notice that the first character of each string in the team column has been removed.

Note that the nchar() function is used to calculate the total number of characters in a string.

Thus, we use the substr() function to extract the substring ranging from the second character to the last character in each string, which is equivalent to removing the first character from each string.

Note: If you’d like to remove the first character from strings in multiple columns, simply include multiple column names in the across() function.

Additional Resources

The following tutorials explain how to perform other common tasks in dplyr:

How to Remove Rows Using dplyr
How to Select Columns by Index Using dplyr
How to Filter Rows that Contain a Certain String Using dplyr

Featured Posts

Leave a Reply

Your email address will not be published. Required fields are marked *