Improve __str__ handling of optional parameters

boule/_ellipsoid.py

@@ -89,7 +89,16 @@ class Ellipsoid:
     ...     ),
     ... )
     >>> print(ellipsoid) # doctest: +ELLIPSIS
-    Ellipsoid(name='WGS84', ...)
+    WGS84 - World Geodetic System 1984
+    Oblate ellipsoid:
+      Semimajor axis: 6378137 m
+      Flattening: 0.0033528106647474805
+      GM: 398600441800000.0 m³/s²
+      Angular velocity: 7.292115e-05 rad/s
+    Source:
+      Hofmann-Wellenhof, B., & Moritz, H. (2006). Physical Geodesy (2nd,
+      corr. ed. 2006 edition ed.). Wien ; New York: Springer.
+
     >>> print(ellipsoid.long_name)
     World Geodetic System 1984
 
@@ -396,17 +405,23 @@ def gravity_pole(self):
         return result
 
     def __str__(self):
-        str = self.name + " - " + self.long_name + "\n"
-        str += "Oblate ellipsoid:\n"
-        str += f"  Semimajor axis: {self.semimajor_axis} m\n"
-        str += f"  Flattening: {self.flattening}\n"
-        str += f"  GM: {self.geocentric_grav_const} m³/s²\n"
-        str += f"  Angular velocity: {self.angular_velocity} rad/s\n"
-        str += "Source:\n"
-        str += textwrap.fill(
-            self.reference, width=72, initial_indent="  ", subsequent_indent="  "
-        )
-        return str
+        s = self.name + " - " + self.long_name + "\n"
+        s += "Oblate ellipsoid:\n"
+        s += f"  Semimajor axis: {self.semimajor_axis} m\n"
+        s += f"  Flattening: {self.flattening}\n"
+        s += f"  GM: {self.geocentric_grav_const} m³/s²\n"
+        s += f"  Angular velocity: {self.angular_velocity} rad/s"
+        if self.reference is not None:
+            s += "\nSource:\n"
+            s += textwrap.fill(
+                self.reference, width=72, initial_indent="  ", subsequent_indent="  "
+            )
+        if self.comments is not None:
+            s += "\nComments:\n"
+            s += textwrap.fill(
+                self.comments, width=72, initial_indent="  ", subsequent_indent="  "
+            )
+        return s
 
     def geocentric_radius(self, latitude, geodetic=True):
         r"""

boule/_sphere.py

@@ -82,7 +82,12 @@ class Sphere:
     ...     angular_velocity=0.5,
     ... )
     >>> print(sphere) # doctest: +ELLIPSIS
-    Sphere(name='Moon', ...)
+    Moon - That's no moon
+    Spheroid:
+      Radius: 1 m
+      GM: 2 m³/s²
+      Angular velocity: 0.5 rad/s
+
     >>> print(sphere.long_name)
     That's no moon
 
@@ -282,16 +287,22 @@ def reference_normal_gravitational_potential(self):
         return self.geocentric_grav_const / self.radius
 
     def __str__(self):
-        str = self.name + " - " + self.long_name + "\n"
-        str += "Spheroid:\n"
-        str += f"  Radius: {self.radius} m\n"
-        str += f"  GM: {self.geocentric_grav_const} m³/s²\n"
-        str += f"  Angular velocity: {self.angular_velocity} rad/s\n"
-        str += "Source:\n"
-        str += textwrap.fill(
-            self.reference, width=72, initial_indent="  ", subsequent_indent="  "
-        )
-        return str
+        s = self.name + " - " + self.long_name + "\n"
+        s += "Spheroid:\n"
+        s += f"  Radius: {self.radius} m\n"
+        s += f"  GM: {self.geocentric_grav_const} m³/s²\n"
+        s += f"  Angular velocity: {self.angular_velocity} rad/s"
+        if self.reference is not None:
+            s += "\nSource:\n"
+            s += textwrap.fill(
+                self.reference, width=72, initial_indent="  ", subsequent_indent="  "
+            )
+        if self.comments is not None:
+            s += "\nComments:\n"
+            s += textwrap.fill(
+                self.comments, width=72, initial_indent="  ", subsequent_indent="  "
+            )
+        return s
 
     def normal_gravity(self, latitude, height, si_units=False):
         r"""

boule/_triaxialellipsoid.py

@@ -85,44 +85,59 @@ class TriaxialEllipsoid:
     We can define an ellipsoid by setting the 5 key numerical parameters:
 
     >>> ellipsoid = TriaxialEllipsoid(
-    ...     name="VESTA",
+    ...     name="Vesta",
     ...     long_name="Vesta Triaxial Ellipsoid",
-    ...     semimajor_axis=286_300,
-    ...     semimedium_axis=278_600,
-    ...     semiminor_axis=223_200,
-    ...     geocentric_grav_const=1.729094e10,
-    ...     angular_velocity=326.71050958367e-6,
+    ...     semimajor_axis=280_413,
+    ...     semimedium_axis=274_572,
+    ...     semiminor_axis=231_253,
+    ...     geocentric_grav_const=17.288e9,
+    ...     angular_velocity=3.267e-4,
+    ...     semimajor_axis_longitude=8.29,
     ...     reference=(
-    ...         "Russell, C. T., Raymond, C. A., Coradini, A., McSween, "
-    ...         "H. Y., Zuber, M. T., Nathues, A., et al. (2012). Dawn at "
-    ...         "Vesta: Testing the Protoplanetary Paradigm. Science. "
-    ...         "doi:10.1126/science.1219381"
+    ...         "Karimi, R., Azmoudeh Ardalan, A., & Vasheghani Farahani, S. "
+    ...         "(2017). The size, shape and orientation of the asteroid "
+    ...         "Vesta based on data from the Dawn mission. Earth and "
+    ...         "Planetary Science Letters, 475, 71–82. "
+    ...         "https://doi.org/10.1016/j.epsl.2017.07.033"
     ...     ),
     ... )
     >>> print(ellipsoid) # doctest: +ELLIPSIS
-    TriaxialEllipsoid(name='VESTA', ...)
+    Vesta - Vesta Triaxial Ellipsoid
+    Triaxial ellipsoid:
+      Semimajor axis: 280413 m
+      Semimedium axis: 274572 m
+      Semiminor axis: 231253 m
+      Semiminor axis longitude: 8.29
+      GM: 17288000000.0 m³/s²
+      Angular velocity: 0.0003267 rad/s
+    Source:
+      Karimi, R., Azmoudeh Ardalan, A., & Vasheghani Farahani, S. (2017).
+      The size, shape and orientation of the asteroid Vesta based on data
+      from the Dawn mission. Earth and Planetary Science Letters, 475,
+      71–82. https://doi.org/10.1016/j.epsl.2017.07.033
+
     >>> print(ellipsoid.long_name)
     Vesta Triaxial Ellipsoid
 
     The class then defines several derived attributes based on the input
     parameters:
 
     >>> print(f"{ellipsoid.mean_radius:.0f} m")
-    259813 m
+    260344 m
     >>> print(f"{ellipsoid.semiaxes_mean_radius:.0f} m")
-    262700 m
+    262079 m
     >>> print(f"{ellipsoid.area:.10e} m²")
-    8.6562393883e+11 m²
+    8.6210266337e+11 m²
     >>> print(f"{ellipsoid.area_equivalent_radius:0.0f} m")
-    262458 m
+    261924 m
     >>> print(f"{ellipsoid.volume_equivalent_radius:.0f} m")
-    261115 m
+    261124 m
     >>> print(f"{ellipsoid.mass:.10e} kg")
-    2.5906746775e+20 kg
+    2.5902341819e+20 kg
     >>> print(f"{ellipsoid.mean_density:.0f} kg/m³")
-    3474 kg/m³
+    3473 kg/m³
     >>> print(f"{ellipsoid.volume * 1e-9:.0f} km³")
-    74573626 km³
+    74581373 km³
 
     """
 
@@ -327,18 +342,25 @@ def meridional_flattening(self):
         return (self.semimajor_axis - self.semiminor_axis) / self.semimajor_axis
 
     def __str__(self):
-        str = self.name + " - " + self.long_name + "\n"
-        str += "Triaxial ellipsoid:\n"
-        str += f"  Semimajor axis: {self.semimajor_axis} m\n"
-        str += f"  Semimedium axis: {self.semimedium_axis} m\n"
-        str += f"  Semiminor axis: {self.semiminor_axis} m\n"
-        str += f"  GM: {self.geocentric_grav_const} m³/s²\n"
-        str += f"  Angular velocity: {self.angular_velocity} rad/s\n"
-        str += "Source:\n"
-        str += textwrap.fill(
-            self.reference, width=72, initial_indent="  ", subsequent_indent="  "
-        )
-        return str
+        s = self.name + " - " + self.long_name + "\n"
+        s += "Triaxial ellipsoid:\n"
+        s += f"  Semimajor axis: {self.semimajor_axis} m\n"
+        s += f"  Semimedium axis: {self.semimedium_axis} m\n"
+        s += f"  Semiminor axis: {self.semiminor_axis} m\n"
+        s += f"  Semiminor axis longitude: {self.semimajor_axis_longitude}\n"
+        s += f"  GM: {self.geocentric_grav_const} m³/s²\n"
+        s += f"  Angular velocity: {self.angular_velocity} rad/s"
+        if self.reference is not None:
+            s += "\nSource:\n"
+            s += textwrap.fill(
+                self.reference, width=72, initial_indent="  ", subsequent_indent="  "
+            )
+        if self.comments is not None:
+            s += "\nComments:\n"
+            s += textwrap.fill(
+                self.comments, width=72, initial_indent="  ", subsequent_indent="  "
+            )
+        return s
 
     def geocentric_radius(self, longitude, latitude):
         r"""