tt_string_info function

Table Transformer: obtain a summary table for string columns

With any table object, you can produce a summary table that is scoped to string-based columns. The output summary table will have a leading column called ".param." with labels for each of the three rows, each corresponding to the following pieces of information pertaining to string length:

1. Mean String Length ("length_mean")
2. Minimum String Length ("length_min")
3. Maximum String Length ("length_max")

Only string data from the input table will generate columns in the output table. Column names from the input will be used in the output, preserving order as well.

tt_string_info(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.

Returns

A tibble object.

Examples

Get string information for the string-based columns in the game_revenue

dataset that is included in the pointblank package.

tt_string_info(tbl = game_revenue)
#> # A tibble: 3 x 7
#>   .param.     player_id session_id item_type item_name acquisition country
#>   <chr>           <dbl>      <dbl>     <dbl>     <dbl>       <dbl>   <dbl>
#> 1 length_mean        15         24      2.22      7.35        7.97    8.53
#> 2 length_min         15         24      2         5           5       5   
#> 3 length_max         15         24      3        11          14      14

Ensure that player_id and session_id values always have the same fixed numbers of characters (15 and 24, respectively) throughout the table.

tt_string_info(tbl = game_revenue) %>%
  col_vals_equal(
    columns = player_id,
    value = 15
  ) %>%
  col_vals_equal(
    columns = session_id,
    value = 24
  )
#> # A tibble: 3 x 7
#>   .param.     player_id session_id item_type item_name acquisition country
#>   <chr>           <dbl>      <dbl>     <dbl>     <dbl>       <dbl>   <dbl>
#> 1 length_mean        15         24      2.22      7.35        7.97    8.53
#> 2 length_min         15         24      2         5           5       5   
#> 3 length_max         15         24      3        11          14      14

We see data, and not an error, so both validations were successful!

Let's use a tt_string_info()-transformed table with the test_col_vals_lte() to check that the maximum string length in column f

of the small_table dataset is no greater than 4.

tt_string_info(tbl = small_table) %>%
  test_col_vals_lte(
    columns = f,
    value = 4
  )
#> [1] TRUE

Function ID

12-2

See Also

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