Fix representation for single constraints without coordinates

doc/release_notes.rst

@@ -1,8 +1,11 @@
 Release Notes
 =============
 
-.. Upcoming Release
-.. ----------------
+Upcoming Release
+----------------
+
+* Fix display for constraint with single entry and no coordinates.
+
 
 Version 0.1.1
 -------------

linopy/common.py

@@ -115,14 +115,16 @@ def print_single_expression(c, v, model):
     """
     # catch case that to many terms would be printed
     def print_line(expr):
-        res = ""
+        res = []
         for i, (coeff, (name, coord)) in enumerate(expr):
             coord_string = print_coord(coord)
             if i:
-                res += f" {float(coeff):+.4} {name}{coord_string} "
+                # split sign and coefficient
+                coeff_string = f"{float(coeff):+.4}"
+                res.append(f"{coeff_string[0]} {coeff_string[1:]} {name}{coord_string}")
             else:
-                res += f" {float(coeff):.4} {name}{coord_string} "
-        return res if res else " None"
+                res.append(f"{float(coeff):.4} {name}{coord_string}")
+        return " ".join(res) if len(res) else "None"
 
     if isinstance(c, np.ndarray):
         mask = v != -1
@@ -133,7 +135,7 @@ def print_line(expr):
         truncate = max_terms // 2
         expr = list(zip(c[:truncate], model.variables.get_label_position(v[:truncate])))
         res = print_line(expr)
-        res += "... "
+        res += " ... "
         expr = list(
             zip(c[-truncate:], model.variables.get_label_position(v[-truncate:]))
         )

linopy/constraints.py

@@ -103,25 +103,25 @@ def __repr__(self):
         Get the string representation of the Constraint.
         """
         # return single if only one exist
-        if self.size == self.nterm:
+        if self.lhs.size == self.nterm:
             expr_string = print_single_expression(
                 self.lhs.coeffs.values, self.lhs.vars.values, self.lhs.model
             )
-            header = f"{self.type} `{self.name}`\n" + "-" * (
-                len(self.type) + len(self.name) + 3
-            )
+            name_string = f" `{self.name}`" if self.name else ""
+            header_string = str(self.type) + name_string
+            header = f"{header_string}\n" + "-" * (len(header_string))
             return f"{header}\n{expr_string} {self.sign.item()} {self.rhs.item()}"
 
         # create header string
+        name_string = f"`{self.name}`" if self.name else ""
         shape_string = ", ".join(
             [f"{self.dims[i]}: {self.shape[i]}" for i in range(self.ndim)]
         )
         shape_string = f"({shape_string})"
         n_masked = (~self.mask).sum().item()
         mask_string = f" - {n_masked} masked entries" if n_masked else ""
-        header = f"{self.type} `{self.name}` {shape_string}{mask_string}\n" + "-" * (
-            len(self.type) + len(self.name) + len(shape_string) + len(mask_string) + 4
-        )
+        header_string = f"{self.type} {name_string} {shape_string}" + mask_string
+        header = f"{header_string}\n" + "-" * (len(header_string))
 
         # create data string, print only a few values
         max_print = options["display_max_rows"]

linopy/variables.py

@@ -192,8 +192,10 @@ def __repr__(self):
             lower = self.lower.item()
             upper = self.upper.item()
             coord = []
-            data_string = print_single_variable(self, self.name, coord, lower, upper)
-            return f"{header}\n{data_string}"
+            var_string, bound_string = print_single_variable(
+                self, self.name, coord, lower, upper
+            )
+            return f"{header}\n{var_string} {bound_string}"
 
         # create header string
         if self.shape:

test/test_repr.py

@@ -99,7 +99,15 @@ def test_linear_expression_long():
 
 
 def test_scalar_linear_expression_repr():
-    repr(1 * u[0, 0])
+    for var in [u, v, x, y, z, a, b, c, d]:
+        coord = tuple([var.indexes[c][0] for c in var.dims])
+        repr(1 * var[coord])
+
+
+def test_single_linear_repr():
+    for var in [u, v, x, y, z, a, b, c, d]:
+        coord = tuple([var.indexes[c][0] for c in var.dims])
+        repr(1 * var.loc[coord])
 
 
 def test_anonymous_constraint_repr():
@@ -111,6 +119,13 @@ def test_scalar_constraint_repr():
     repr(1 * u[0, 0] >= 0)
 
 
+def test_single_constraint_repr():
+    for var in [u, v, x, y, z, a, b, c, d]:
+        coord = tuple([var.indexes[c][0] for c in var.dims])
+        repr(1 * var.loc[coord] == 0)
+        repr(1 * var.loc[coord] - var.loc[coord] == 0)
+
+
 def test_constraint_repr():
     for con in [cu, cv, cx, cy, cz, ca, cb, cc, cd, cav, cu_masked]:
         repr(con)