Table Transformer: get a table's column names

With any table object, you can produce a summary table that contains table's column names. The output summary table will have two columns and as many rows as there are columns in the input table. The first column is the ".param." column, which is an integer-based column containing the indices of the columns from the input table. The second column, "value", contains the column names from the input table.

Usage

tt_tbl_colnames(tbl)

Arguments

tbl

A data table

obj:<tbl_*> // required

A table object to be used as input for the transformation. This can be a data frame, a tibble, a tbl_dbi object, or a tbl_spark object.

Value

A tibble object.

Examples

Get the column names of the game_revenue dataset that is included in the pointblank package.

tt_tbl_colnames(tbl = game_revenue)
#> # A tibble: 11 x 2
#>    .param. value
#>      <int> <chr>
#>  1       1 player_id
#>  2       2 session_id
#>  3       3 session_start
#>  4       4 time
#>  5       5 item_type
#>  6       6 item_name
#>  7       7 item_revenue
#>  8       8 session_duration
#>  9       9 start_day
#> 10      10 acquisition
#> 11      11 country

This output table is useful when you want to validate the column names of the table. Here, we check that game_revenue table, included in the pointblank package, has certain column names present with test_col_vals_make_subset().

tt_tbl_colnames(tbl = game_revenue) %>%
  test_col_vals_make_subset(
    columns = value,
    set = c("acquisition", "country")
  )
#> [1] TRUE

We can check to see whether the column names in the specifications table are all less than 15 characters in length. For this, we would use the combination of tt_tbl_colnames(), then tt_string_info(), and finally test_col_vals_lt() to perform the test.

specifications %>%
  tt_tbl_colnames() %>%
  tt_string_info() %>%
  test_col_vals_lt(
    columns = value,
    value = 15
  )
#> [1] FALSE

This returned FALSE and this is because the column name credit_card_numbers is 16 characters long.

Function ID

12-4

See also

Other Table Transformers: get_tt_param(), tt_string_info(), tt_summary_stats(), tt_tbl_dims(), tt_time_shift(), tt_time_slice()