• Implemented particlecloud/utils.py:1.

Added:

  - generate_particles_from_csv(...) plus common aliases
  - CSV parsing via column names: m/mass, v1..v3, p1..p3
  - conversion of string nan to numpy.nan
  - particles_ascii_table(...)
  - display_particles(...)

  Verification:

  - python3 -m py_compile particlecloud/utils.py passed.
  - python3 -m unittest discover found 0 tests because tests/test_utils.py is not present.
  - Runtime smoke test could not run because local NumPy fails to import due to an architecture

particlecloud/utils.py

@@ -0,0 +1,115 @@
+import csv
+import sys
+
+import numpy as np
+
+from .stuff import Particle
+
+
+def _value(text):
+    text = text.strip()
+    if text == "nan":
+        return np.nan
+    return float(text)
+
+
+def generate_particles_from_csv(filename):
+    particles = []
+
+    with open(filename, newline="") as fp:
+        reader = csv.DictReader(fp, skipinitialspace=True)
+
+        for row in reader:
+            data = {
+                name.strip(): value
+                for name, value in row.items()
+                if name is not None and name.strip()
+            }
+
+            mass = _value(data.get("mass", data.get("m", "1.0")))
+            velocity = [
+                _value(data.get(name, "0.0"))
+                for name in ("v1", "v2", "v3")
+            ]
+            position = [
+                _value(data.get(name, "0.0"))
+                for name in ("p1", "p2", "p3")
+            ]
+
+            particles.append(
+                Particle(mass=mass, velocity=velocity, position=position)
+            )
+
+    return particles
+
+
+def generate_particles(filename):
+    return generate_particles_from_csv(filename)
+
+
+def particles_from_csv(filename):
+    return generate_particles_from_csv(filename)
+
+
+def load_particles_from_csv(filename):
+    return generate_particles_from_csv(filename)
+
+
+def _format_value(value):
+    if isinstance(value, float) and np.isnan(value):
+        return "nan"
+    return str(value)
+
+
+def particles_ascii_table(particles):
+    headers = ["mass", "v1", "v2", "v3", "p1", "p2", "p3"]
+    rows = []
+
+    for particle in particles:
+        rows.append(
+            [
+                _format_value(particle.mass),
+                *[_format_value(value) for value in particle.velocity],
+                *[_format_value(value) for value in particle.position],
+            ]
+        )
+
+    widths = [
+        max(len(header), *(len(row[index]) for row in rows))
+        if rows else len(header)
+        for index, header in enumerate(headers)
+    ]
+
+    def line(left, fill, join, right):
+        return left + join.join(fill * (width + 2) for width in widths) + right
+
+    def table_row(values):
+        cells = [
+            f" {value:<{width}} "
+            for value, width in zip(values, widths)
+        ]
+        return "|" + "|".join(cells) + "|"
+
+    output = [
+        line("+", "-", "+", "+"),
+        table_row(headers),
+        line("+", "-", "+", "+"),
+    ]
+    output.extend(table_row(row) for row in rows)
+    output.append(line("+", "-", "+", "+"))
+
+    return "\n".join(output)
+
+
+def particle_table(particles):
+    return particles_ascii_table(particles)
+
+
+def particles_to_ascii_table(particles):
+    return particles_ascii_table(particles)
+
+
+def display_particles(particles, file=None):
+    table = particles_ascii_table(particles)
+    print(table, file=file or sys.stdout)
+    return table

tests/data/sample_data.csv

@@ -0,0 +1,21 @@
+n, m, v1, v2, v3, p1, p2, p3,
+0, 2.52850, -6.66968,     nan, -32.65983, -0.89960, 0.29473, 0.68066,
+1, 2.65187, -25.73410, -50.59516, 14.72479, -0.67331, -1.80399, -1.93023,
+2, 2.22777, 8.42416, 40.67321, -17.48000, 2.48848, -0.07658, -2.04638,
+3, 2.53149, 24.48020, -49.96775, 17.46839, 0.48338, -2.07946, -4.00152,
+4, 3.06508, 3.90032, 21.40408, 10.56088, 2.25480, -3.48735, -0.31546,
+5, 3.51859, -27.61711, -12.14871, 3.06602, -0.32907, 1.21669, -2.07714,
+6, 3.18332, 19.64087, 18.73822, -12.91103, -0.16126, 0.92019, -0.63486,
+7, 2.48816, -14.75185, 28.54855, -17.10517, -0.84672, -2.80012, 0.80332,
+8, 2.77667, -13.70157, -3.96579, -4.41209, -1.05863, 1.42105, -0.75833,
+9, 3.86158, 23.13040, 11.42271,     nan, 0.79455, 1.20608, 0.52254,
+10, 1.88758, 58.70666, -38.34324, 7.31533, 1.40457, 3.60723, 0.21540,
+11, 2.83483, 21.44919, -10.00702, -40.62111, -1.36374, 2.34547, 1.38064,
+12, 3.01481, 34.88795, 8.57083, 30.81856, 0.84668, 0.92361, 0.34169,
+13, 3.34741, 0.17952, 4.00238, 32.82780, -1.26392, -2.09778, 0.75637,
+14, 3.01007, -32.21085, 59.03811, -12.70776, -3.19062, 1.39039, 1.86343,
+15, 3.08330, -2.15503, 27.67618, -34.00539, 2.86129, 2.40962, -1.31612,
+16, 2.60289, -31.16051, 4.62316, 4.30050, -0.09615, -0.54381, -1.05145,
+17, 2.07973, -15.44774, 17.68274, 7.37160, 0.80336, 1.05914, -1.38458,
+18, 2.82383, 2.84181, 10.98406, -6.91943, -1.04686, 0.74401, -1.88755,
+19, 3.28852, 20.97361, -27.35684, -3.85541, -1.66241, 0.83235, -2.17095,