R readr spec 检查 DataFrame 的列规格

cols_condense(x)

spec(x)

其他解析器：col_skip() , cols() , parse_datetime() , parse_factor() , parse_guess() , parse_logical() , parse_number() , parse_vector()

df <- read_csv(readr_example("mtcars.csv"))
#> Rows: 32 Columns: 11
#> ── Column specification ──────────────────────────────────────────────────
#> Delimiter: ","
#> dbl (11): mpg, cyl, disp, hp, drat, wt, qsec, vs, am, gear, carb
#> 
#> ℹ Use `spec()` to retrieve the full column specification for this data.
#> ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.
s <- spec(df)
s
#> cols(
#>   mpg = col_double(),
#>   cyl = col_double(),
#>   disp = col_double(),
#>   hp = col_double(),
#>   drat = col_double(),
#>   wt = col_double(),
#>   qsec = col_double(),
#>   vs = col_double(),
#>   am = col_double(),
#>   gear = col_double(),
#>   carb = col_double()
#> )

cols_condense(s)
#> cols(
#>   .default = col_double()
#> )