ee

“ee”를 포함한 나라를 찾으려면 어떤 표현을 썼는지 답해주세요.

library(dplyr)

## 
## Attaching package: 'dplyr'

## The following objects are masked from 'package:stats':
## 
##     filter, lag

## The following objects are masked from 'package:base':
## 
##     intersect, setdiff, setequal, union

library(readr)
gap <- read_delim("https://www.stat.ubc.ca/~jenny/notOcto/STAT545A/examples/gapminder/data/gapminderDataFiveYear.txt", 
    "\t", escape_double = FALSE, trim_ws = TRUE)

## Parsed with column specification:
## cols(
##   country = col_character(),
##   year = col_double(),
##   pop = col_double(),
##   continent = col_character(),
##   lifeExp = col_double(),
##   gdpPercap = col_double()
## )

head(gap)

## # A tibble: 6 x 6
##   country      year      pop continent lifeExp gdpPercap
##   <chr>       <dbl>    <dbl> <chr>       <dbl>     <dbl>
## 1 Afghanistan  1952  8425333 Asia         28.8      779.
## 2 Afghanistan  1957  9240934 Asia         30.3      821.
## 3 Afghanistan  1962 10267083 Asia         32.0      853.
## 4 Afghanistan  1967 11537966 Asia         34.0      836.
## 5 Afghanistan  1972 13079460 Asia         36.1      740.
## 6 Afghanistan  1977 14880372 Asia         38.4      786.

gap_country <- gap %>% group_by(gap$country) %>% summarise(n = n())

## `summarise()` ungrouping output (override with `.groups` argument)

head(gap_country)

## # A tibble: 6 x 2
##   `gap$country`     n
##   <chr>         <int>
## 1 Afghanistan      12
## 2 Albania          12
## 3 Algeria          12
## 4 Angola           12
## 5 Argentina        12
## 6 Australia        12

grep("e{2}", gap_country$`gap$country`, value = T)

## [1] "Greece"