feat!: Add check_names parameter to Series.equals and default to …

…`False` (#16610)

crates/polars-core/src/testing.rs

@@ -6,18 +6,18 @@ use crate::prelude::*;
 impl Series {
     /// Check if series are equal. Note that `None == None` evaluates to `false`
     pub fn equals(&self, other: &Series) -> bool {
-        if self.null_count() > 0 || other.null_count() > 0 || self.dtype() != other.dtype() {
+        if self.null_count() > 0 || other.null_count() > 0 {
             false
         } else {
             self.equals_missing(other)
         }
     }
 
     /// Check if all values in series are equal where `None == None` evaluates to `true`.
-    /// Two [`Datetime`](DataType::Datetime) series are *not* equal if their timezones are different, regardless
-    /// if they represent the same UTC time or not.
     pub fn equals_missing(&self, other: &Series) -> bool {
         match (self.dtype(), other.dtype()) {
+            // Two [`Datetime`](DataType::Datetime) series are *not* equal if their timezones
+            // are different, regardless if they represent the same UTC time or not.
             #[cfg(feature = "timezones")]
             (DataType::Datetime(_, tz_lhs), DataType::Datetime(_, tz_rhs)) => {
                 if tz_lhs != tz_rhs {
@@ -27,17 +27,14 @@ impl Series {
             _ => {},
         }
 
-        // differences from Partial::eq in that numerical dtype may be different
-        self.len() == other.len()
-            && self.name() == other.name()
-            && self.null_count() == other.null_count()
-            && {
-                let eq = self.equal_missing(other);
-                match eq {
-                    Ok(b) => b.all(),
-                    Err(_) => false,
-                }
+        // Differs from Partial::eq in that numerical dtype may be different
+        self.len() == other.len() && self.null_count() == other.null_count() && {
+            let eq = self.equal_missing(other);
+            match eq {
+                Ok(b) => b.all(),
+                Err(_) => false,
             }
+        }
     }
 
     /// Get a pointer to the underlying data of this [`Series`].
@@ -99,7 +96,7 @@ impl DataFrame {
             return false;
         }
         for (left, right) in self.get_columns().iter().zip(other.get_columns()) {
-            if !left.equals(right) {
+            if left.name() != right.name() || !left.equals(right) {
                 return false;
             }
         }
@@ -125,7 +122,7 @@ impl DataFrame {
             return false;
         }
         for (left, right) in self.get_columns().iter().zip(other.get_columns()) {
-            if !left.equals_missing(right) {
+            if left.name() != right.name() || !left.equals_missing(right) {
                 return false;
             }
         }
@@ -191,10 +188,11 @@ mod test {
     }
 
     #[test]
-    fn test_series_dtype_noteq() {
+    fn test_series_dtype_not_equal() {
         let s_i32 = Series::new("a", &[1_i32, 2_i32]);
         let s_i64 = Series::new("a", &[1_i64, 2_i64]);
-        assert!(!s_i32.equals(&s_i64));
+        assert!(s_i32.dtype() != s_i64.dtype());
+        assert!(s_i32.equals(&s_i64));
     }
 
     #[test]

py-polars/polars/series/series.py

@@ -4120,6 +4120,7 @@ def equals(
         other: Series,
         *,
         check_dtypes: bool = False,
+        check_names: bool = False,
         null_equal: bool = True,
     ) -> bool:
         """
@@ -4131,6 +4132,8 @@ def equals(
             Series to compare with.
         check_dtypes
             Require data types to match.
+        check_names
+            Require names to match.
         null_equal
             Consider null values as equal.
 
@@ -4148,7 +4151,10 @@ def equals(
         False
         """
         return self._s.equals(
-            other._s, check_dtypes=check_dtypes, null_equal=null_equal
+            other._s,
+            check_dtypes=check_dtypes,
+            check_names=check_names,
+            null_equal=null_equal,
         )
 
     def cast(

py-polars/src/series/mod.rs

@@ -324,10 +324,19 @@ impl PySeries {
         self.series.has_validity()
     }
 
-    fn equals(&self, other: &PySeries, check_dtypes: bool, null_equal: bool) -> bool {
+    fn equals(
+        &self,
+        other: &PySeries,
+        check_dtypes: bool,
+        check_names: bool,
+        null_equal: bool,
+    ) -> bool {
         if check_dtypes && (self.series.dtype() != other.series.dtype()) {
             return false;
         }
+        if check_names && (self.series.name() != other.series.name()) {
+            return false;
+        }
         if null_equal {
             self.series.equals_missing(&other.series)
         } else {

py-polars/tests/unit/series/test_equals.py

@@ -30,6 +30,13 @@ def test_equals() -> None:
     assert s3.dt.convert_time_zone("Asia/Tokyo").equals(s4) is True
 
 
+def test_series_equals_check_names() -> None:
+    s1 = pl.Series("foo", [1, 2, 3])
+    s2 = pl.Series("bar", [1, 2, 3])
+    assert s1.equals(s2) is True
+    assert s1.equals(s2, check_names=True) is False
+
+
 def test_eq_list_cmp_list() -> None:
     s = pl.Series([[1], [1, 2]])
     result = s == [1, 2]