CODEWITHSUNDEEP
r
Doug Fir
Doug Fir

Reputation: 21282

Replace any data points with spaces with underscores across any and all columns

Suppose I have a data frame with some columns containing text and that in some cases there are spaces. In those cases I would like to replace the spaces with underscores.

e.g.

library(dplyr)
library(stringr)
my_mtcars <- mtcars %>% rownames_to_column()

In this case there is only one column, 'rowname' which contains text. But in my real world example my df may have a variable number of fields containing text that I would like to apply this transformation on.

Tried:

my_mtcars %>% mutate_at(any_vars, str_replace_all(' ', '_'))
Error: `.vars` must be a character/numeric vector or a `vars()` object, not a function

Then tried:

my_mtcars %>% mutate_all(str_replace_all(' ', '_'))
Error in fix_replacement(replacement) : 
  argument "replacement" is missing, with no default

How can I transform any features with text data so that any spaces are replaced with underscores?

Upvotes: 2

Views: 1328

Answers (3)

Haci Duru
Haci Duru

Reputation: 456

You can use something like this:

my_mtcars = data.frame(val = row.names(mtcars))

> head(my_mtcars)
                val
1         Mazda RX4
2     Mazda RX4 Wag
3        Datsun 710
4    Hornet 4 Drive
5 Hornet Sportabout
6           Valiant

my_mtcars$val = apply(my_mtcars, 1, function(x) gsub(" ", "_", x))
> head(my_mtcars)
                val
1         Mazda_RX4
2     Mazda_RX4_Wag
3        Datsun_710
4    Hornet_4_Drive
5 Hornet_Sportabout
6           Valiant

Upvotes: 1

Greg
Greg

Reputation: 3670

You can use another scoped variant of mutate, namely mutate_all

library(dplyr)
library(stringr)

my_mtcars %>% 
  mutate_all( ~ str_replace_all(., " ", "_")) %>%
  head()
            rowname  mpg cyl disp  hp drat    wt  qsec vs am gear carb
1         Mazda_RX4   21   6  160 110  3.9  2.62 16.46  0  1    4    4
2     Mazda_RX4_Wag   21   6  160 110  3.9 2.875 17.02  0  1    4    4
3        Datsun_710 22.8   4  108  93 3.85  2.32 18.61  1  1    4    1
4    Hornet_4_Drive 21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
5 Hornet_Sportabout 18.7   8  360 175 3.15  3.44 17.02  0  0    3    2
6           Valiant 18.1   6  225 105 2.76  3.46 20.22  1  0    3    1

Upvotes: 1

Allan Cameron
Allan Cameron

Reputation: 174328

You need to pass the additional arguments to str_replace_all to the ... in mutate_if rather than within parentheses (similar to apply type functions):

my_mtcars %>% mutate_if(is.character, str_replace_all, ' ', '_')
#>                rowname  mpg cyl  disp  hp drat    wt  qsec vs am gear carb
#> 1            Mazda_RX4 21.0   6 160.0 110 3.90 2.620 16.46  0  1    4    4
#> 2        Mazda_RX4_Wag 21.0   6 160.0 110 3.90 2.875 17.02  0  1    4    4
#> 3           Datsun_710 22.8   4 108.0  93 3.85 2.320 18.61  1  1    4    1
#> 4       Hornet_4_Drive 21.4   6 258.0 110 3.08 3.215 19.44  1  0    3    1
#> 5    Hornet_Sportabout 18.7   8 360.0 175 3.15 3.440 17.02  0  0    3    2
#> 6              Valiant 18.1   6 225.0 105 2.76 3.460 20.22  1  0    3    1
#> 7           Duster_360 14.3   8 360.0 245 3.21 3.570 15.84  0  0    3    4
#> 8            Merc_240D 24.4   4 146.7  62 3.69 3.190 20.00  1  0    4    2
#> 9             Merc_230 22.8   4 140.8  95 3.92 3.150 22.90  1  0    4    2
#> 10            Merc_280 19.2   6 167.6 123 3.92 3.440 18.30  1  0    4    4
#> 11           Merc_280C 17.8   6 167.6 123 3.92 3.440 18.90  1  0    4    4
#> 12          Merc_450SE 16.4   8 275.8 180 3.07 4.070 17.40  0  0    3    3
#> 13          Merc_450SL 17.3   8 275.8 180 3.07 3.730 17.60  0  0    3    3
#> 14         Merc_450SLC 15.2   8 275.8 180 3.07 3.780 18.00  0  0    3    3
#> 15  Cadillac_Fleetwood 10.4   8 472.0 205 2.93 5.250 17.98  0  0    3    4
#> 16 Lincoln_Continental 10.4   8 460.0 215 3.00 5.424 17.82  0  0    3    4
#> 17   Chrysler_Imperial 14.7   8 440.0 230 3.23 5.345 17.42  0  0    3    4
#> 18            Fiat_128 32.4   4  78.7  66 4.08 2.200 19.47  1  1    4    1
#> 19         Honda_Civic 30.4   4  75.7  52 4.93 1.615 18.52  1  1    4    2
#> 20      Toyota_Corolla 33.9   4  71.1  65 4.22 1.835 19.90  1  1    4    1
#> 21       Toyota_Corona 21.5   4 120.1  97 3.70 2.465 20.01  1  0    3    1
#> 22    Dodge_Challenger 15.5   8 318.0 150 2.76 3.520 16.87  0  0    3    2
#> 23         AMC_Javelin 15.2   8 304.0 150 3.15 3.435 17.30  0  0    3    2
#> 24          Camaro_Z28 13.3   8 350.0 245 3.73 3.840 15.41  0  0    3    4
#> 25    Pontiac_Firebird 19.2   8 400.0 175 3.08 3.845 17.05  0  0    3    2
#> 26           Fiat_X1-9 27.3   4  79.0  66 4.08 1.935 18.90  1  1    4    1
#> 27       Porsche_914-2 26.0   4 120.3  91 4.43 2.140 16.70  0  1    5    2
#> 28        Lotus_Europa 30.4   4  95.1 113 3.77 1.513 16.90  1  1    5    2
#> 29      Ford_Pantera_L 15.8   8 351.0 264 4.22 3.170 14.50  0  1    5    4
#> 30        Ferrari_Dino 19.7   6 145.0 175 3.62 2.770 15.50  0  1    5    6
#> 31       Maserati_Bora 15.0   8 301.0 335 3.54 3.570 14.60  0  1    5    8
#> 32          Volvo_142E 21.4   4 121.0 109 4.11 2.780 18.60  1  1    4    2

``z

Upvotes: 1

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