feat(rust): Add "fmt_no_tty" feature for formatting support without r… (

#5725)

polars/Cargo.toml

@@ -61,6 +61,7 @@ performant = ["polars-core/performant", "chunked_ids", "dtype-u8", "dtype-u16",
 
 # Dataframe formatting.
 fmt = ["polars-core/fmt"]
+fmt_no_tty = ["polars-core/fmt_no_tty"]
 
 # sort by multiple columns
 sort_multiple = ["polars-core/sort_multiple"]

polars/polars-core/Cargo.toml

@@ -29,7 +29,8 @@ string_encoding = ["base64", "hex"]
 # support for ObjectChunked<T> (downcastable Series of any type)
 object = ["serde_json"]
 
-fmt = ["comfy-table"]
+fmt = ["comfy-table/tty"]
+fmt_no_tty = ["comfy-table"]
 
 # opt-in features
 # sort by multiple columns
@@ -151,7 +152,7 @@ base64 = { version = "0.13", optional = true }
 bitflags.workspace = true
 chrono = { version = "0.4", optional = true }
 chrono-tz = { version = "0.6", optional = true }
-comfy-table = { version = "6.1.1", optional = true }
+comfy-table = { version = "6.1.1", optional = true, default_features = false }
 hashbrown.workspace = true
 hex = { version = "0.4", optional = true }
 indexmap = { version = "1", features = ["std"] }

polars/polars-core/src/fmt.rs

@@ -1,4 +1,4 @@
-#[cfg(feature = "fmt")]
+#[cfg(any(feature = "fmt", feature = "fmt_no_tty"))]
 use std::borrow::Cow;
 use std::fmt;
 use std::fmt::{Debug, Display, Formatter};
@@ -11,9 +11,9 @@ use std::fmt::{Debug, Display, Formatter};
 use arrow::temporal_conversions::*;
 #[cfg(feature = "timezones")]
 use chrono::TimeZone;
-#[cfg(feature = "fmt")]
+#[cfg(any(feature = "fmt", feature = "fmt_no_tty"))]
 use comfy_table::presets::*;
-#[cfg(feature = "fmt")]
+#[cfg(any(feature = "fmt", feature = "fmt_no_tty"))]
 use comfy_table::*;
 use num::{Num, NumCast};
 
@@ -295,7 +295,7 @@ impl Debug for DataFrame {
         Display::fmt(self, f)
     }
 }
-#[cfg(feature = "fmt")]
+#[cfg(any(feature = "fmt", feature = "fmt_no_tty"))]
 fn make_str_val(v: &str, truncate: usize) -> String {
     let v_trunc = &v[..v
         .char_indices()
@@ -310,7 +310,7 @@ fn make_str_val(v: &str, truncate: usize) -> String {
     }
 }
 
-#[cfg(feature = "fmt")]
+#[cfg(any(feature = "fmt", feature = "fmt_no_tty"))]
 fn prepare_row(
     row: Vec<Cow<'_, str>>,
     n_first: usize,
@@ -337,7 +337,7 @@ fn env_is_true(varname: &str) -> bool {
 
 impl Display for DataFrame {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        #[cfg(feature = "fmt")]
+        #[cfg(any(feature = "fmt", feature = "fmt_no_tty"))]
         {
             let height = self.height();
             assert!(
@@ -499,7 +499,12 @@ impl Display for DataFrame {
 
             // if no tbl_width (its not-tty && it is not explicitly set), then set default.
             // this is needed to support non-tty applications
-            if !table.is_tty() && table.width().is_none() {
+            #[cfg(feature = "fmt")]
+            if table.width().is_none() && !table.is_tty() {
+                table.set_width(100);
+            }
+            #[cfg(feature = "fmt_no_tty")]
+            if table.width().is_none() {
                 table.set_width(100);
             }
 
@@ -531,11 +536,11 @@ impl Display for DataFrame {
             }
         }
 
-        #[cfg(not(feature = "fmt"))]
+        #[cfg(not(any(feature = "fmt", feature = "fmt_no_tty")))]
         {
             write!(
                 f,
-                "shape: {:?}\nto see more, compile with the 'fmt' feature",
+                "shape: {:?}\nto see more, compile with the 'fmt' or 'fmt_no_tty' feature",
                 self.shape()
             )?;
         }