Merge pull request #466 from tidyverse/print-args

Add `n`/`max_extra_cols`/`max_footer_lines` args to `print.dtplyr_step`
tidyverse · Feb 19, 2024 · e3786a6 · e3786a6
2 parents fc92809 + 66b22ef
commit e3786a6
Show file tree

Hide file tree

Showing 3 changed files with 81 additions and 2 deletions.
diff --git a/R/step.R b/R/step.R
@@ -176,7 +176,11 @@ pull.dtplyr_step <- function(.data, var = -1, name = NULL, ...) {
 }
 
 #' @export
-print.dtplyr_step <- function(x, ...) {
+print.dtplyr_step <- function(x,
+                              ...,
+                              n = 6,
+                              max_extra_cols = NULL,
+                              max_footer_lines = NULL) {
   dt <- as.data.table(x)
 
   cat_line(cli::style_bold("Source: "), "local data table ", dplyr::dim_desc(dt))
@@ -193,7 +197,14 @@ print.dtplyr_step <- function(x, ...) {
     cat_line(cli::style_bold("Call:   "), expr_text(dt_call(x)))
   }
   cat_line()
-  cat_line(format(as_tibble(dt, .name_repair = "minimal"), n = 6)[-1]) # Hack to remove "A tibble" line
+  cat_line(
+    format(
+      as_tibble(dt, .name_repair = "minimal"),
+      n = n,
+      max_extra_cols = max_extra_cols,
+      max_footer_lines = max_footer_lines
+    )[-1] # Hack to remove "A tibble" line
+  )
   cat_line()
   cat_line(cli::col_silver(
     "# Use as.data.table()/as.data.frame()/as_tibble() to access results"

diff --git a/tests/testthat/_snaps/step.md b/tests/testthat/_snaps/step.md
@@ -56,3 +56,59 @@
       
       # Use as.data.table()/as.data.frame()/as_tibble() to access results
 
+# can print using n/max_extra_cols/max_footer_lines, #464, 
+
+    Code
+      dt <- letters %>% lapply(function(.x) tibble(!!.x := 1:10)) %>% bind_cols() %>%
+        lazy_dt("DT")
+      print(dt, n = 3)
+    Output
+      Source: local data table [10 x 26]
+      Call:   DT
+      
+            a     b     c     d     e     f     g     h     i     j     k     l     m
+        <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int>
+      1     1     1     1     1     1     1     1     1     1     1     1     1     1
+      2     2     2     2     2     2     2     2     2     2     2     2     2     2
+      3     3     3     3     3     3     3     3     3     3     3     3     3     3
+      # i 7 more rows
+      # i 13 more variables: n <int>, o <int>, p <int>, q <int>, r <int>, s <int>,
+      #   t <int>, u <int>, v <int>, w <int>, x <int>, y <int>, z <int>
+      
+      # Use as.data.table()/as.data.frame()/as_tibble() to access results
+    Code
+      print(dt, max_extra_cols = 3)
+    Output
+      Source: local data table [10 x 26]
+      Call:   DT
+      
+            a     b     c     d     e     f     g     h     i     j     k     l     m
+        <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int>
+      1     1     1     1     1     1     1     1     1     1     1     1     1     1
+      2     2     2     2     2     2     2     2     2     2     2     2     2     2
+      3     3     3     3     3     3     3     3     3     3     3     3     3     3
+      4     4     4     4     4     4     4     4     4     4     4     4     4     4
+      5     5     5     5     5     5     5     5     5     5     5     5     5     5
+      6     6     6     6     6     6     6     6     6     6     6     6     6     6
+      # i 4 more rows
+      # i 13 more variables: n <int>, o <int>, p <int>, ...
+      
+      # Use as.data.table()/as.data.frame()/as_tibble() to access results
+    Code
+      print(dt, max_footer_lines = 1)
+    Output
+      Source: local data table [10 x 26]
+      Call:   DT
+      
+            a     b     c     d     e     f     g     h     i     j     k     l     m
+        <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int> <int>
+      1     1     1     1     1     1     1     1     1     1     1     1     1     1
+      2     2     2     2     2     2     2     2     2     2     2     2     2     2
+      3     3     3     3     3     3     3     3     3     3     3     3     3     3
+      4     4     4     4     4     4     4     4     4     4     4     4     4     4
+      5     5     5     5     5     5     5     5     5     5     5     5     5     5
+      6     6     6     6     6     6     6     6     6     6     6     6     6     6
+      # i 4 more rows
+      
+      # Use as.data.table()/as.data.frame()/as_tibble() to access results
+
diff --git a/tests/testthat/test-step.R b/tests/testthat/test-step.R
@@ -29,6 +29,18 @@ test_that("has useful display methods", {
   })
 })
 
+test_that("can print using n/max_extra_cols/max_footer_lines, #464, ", {
+  expect_snapshot({
+    dt <- letters %>%
+      lapply(function(.x) tibble(!!.x := 1:10)) %>%
+      bind_cols() %>%
+      lazy_dt("DT")
+    print(dt, n = 3)
+    print(dt, max_extra_cols = 3)
+    print(dt, max_footer_lines = 1)
+  })
+})
+
 test_that("can evaluate to any data frame type", {
   dt <- lazy_dt(mtcars, "DT")