test updated

Author: prathameshnium

pica/keithley/delta_mode/Instrument_Control/Delta_K6221_K2182_Simple.py

@@ -5,6 +5,7 @@
 
 import pyvisa
 import time
+from pica.utils.parser import parse_keithley_output
 
 # --- Configuration ---
 # Use constants for easier changes later.
@@ -64,11 +65,11 @@ def run_delta_measurement():
             # The 6221 in delta mode returns a string like "Voltage,Resistance"
             raw_data = keithley_6221.query('SENSe:DATA:FRESh?')
 
-            # Split the string at the comma to get a list of values
-            data_points = raw_data.strip().split(',')
+            # Use the new parsing function
+            data_points = parse_keithley_output(raw_data)
 
-            # The first item is Voltage, the second is Resistance
-            voltage = float(data_points[0])
+            # The first item is Voltage
+            voltage = data_points[0]
             # Use the resistance calculated by the keithley_6221
             resistance = float(voltage / DELTA_CURRENT)
 

pica/utils/parser.py

@@ -0,0 +1,22 @@
+"""
+This module provides utility functions for parsing data from instruments.
+"""
+
+def parse_keithley_output(data_string: str) -> list[float]:
+    """
+    Parses a comma-separated string of scientific notation numbers from a Keithley instrument
+    and returns a list of floats.
+
+    Args:
+        data_string: A string containing comma-separated numbers,
+                     e.g., "+1.234E-06,+4.567E+00".
+
+    Returns:
+        A list of floats parsed from the string.
+    """
+    try:
+        parts = data_string.strip().split(',')
+        return [float(part) for part in parts]
+    except (ValueError, IndexError) as e:
+        raise ValueError(f"Failed to parse data string: '{data_string}'. Reason: {e}") from e
+

tests/test_backends_logic.py

@@ -85,6 +85,43 @@ def test_delta_backend_structure():
         else:
             print("\n[Delta] Flat script verified (ran on import).")
 
+# ---------------------------------------------------------------------------
+# 4. Data Parsing Test
+# ---------------------------------------------------------------------------
+def test_keithley_data_parser():
+    """
+    Tests the utility function that parses comma-separated scientific notation strings.
+    This is a functional test, not just a structural one.
+    """
+    try:
+        from pica.utils.parser import parse_keithley_output
+    except ImportError:
+        pytest.skip("Could not import the parser module.")
+
+    # Test case 1: Standard scientific notation
+    raw_string_1 = "+1.2345E-06,+2.5000E+00"
+    expected_1 = [1.2345e-6, 2.5]
+    assert parse_keithley_output(raw_string_1) == expected_1, "Failed on standard scientific notation."
+    print(f"\n[Parser] Verified: '{raw_string_1}' -> {expected_1}")
+
+    # Test case 2: Negative values and different spacing
+    raw_string_2 = "-5.0E-03, -1.0E+01"
+    expected_2 = [-0.005, -10.0]
+    assert parse_keithley_output(raw_string_2) == expected_2, "Failed on negative values."
+    print(f"[Parser] Verified: '{raw_string_2}' -> {expected_2}")
+
+    # Test case 3: Single value
+    raw_string_3 = "+3.14159E+00"
+    expected_3 = [3.14159]
+    assert parse_keithley_output(raw_string_3) == expected_3, "Failed on single value."
+    print(f"[Parser] Verified: '{raw_string_3}' -> {expected_3}")
+
+    # Test case 4: Malformed string (should raise ValueError)
+    with pytest.raises(ValueError):
+        parse_keithley_output("1.23, NOT_A_NUMBER")
+    print("[Parser] Verified: Correctly raises ValueError on malformed string.")
+
+
 # ---------------------------------------------------------------------------
 # 3. Keithley 2400 Test
 # ---------------------------------------------------------------------------