Expression evaluator (no eval)
llama3.2-3b
Pythononeshotrun 2sample 012.4s wall← run 2 · raw JSON · challenge definitions
40
score
tests (60%)0/1 passed
deliverables (20%)100%
content checks (20%)100%
01 what the model was asked
Create calc.py with exactly one public function:
evaluate(expr: str) -> float
Evaluate an arithmetic expression containing numbers (integers or decimals), the binary operators + - * /, unary minus, parentheses, and arbitrary whitespace. Normal precedence: * and / bind tighter than + and -; operators of equal precedence associate left to right. Division is true division. Examples: evaluate("2+3*4") == 14, evaluate("(2+3)*4") == 20, evaluate("2*-3") == -6.
You must parse the expression yourself: using eval() or exec() is forbidden and is checked by the test suite. Use only the Python standard library.
required deliverables + checks
✓deliverable: calc.py
✓calc.py must contain “def evaluate”
pytest suite it was graded against
test_calc.py · 36 lines · 688 B
from pathlib import Path from calc import evaluate def test_precedence(): assert evaluate("2+3*4") == 14 def test_parentheses(): assert evaluate("(2+3)*4") == 20 assert evaluate("2*(3+(4-1))") == 12 def test_true_division(): assert evaluate("10/4") == 2.5 def test_left_associativity(): assert evaluate("10-3-2") == 5 assert evaluate("16/4/2") == 2 def test_unary_minus(): assert evaluate("-3+5") == 2 assert evaluate("2*-3") == -6 def test_whitespace_and_decimals(): assert evaluate(" 1.5 + 2.25 ") == 3.75 def test_does_not_use_eval(): src = Path("calc.py").read_text() assert "eval(" not in src assert "exec(" not in src
02 what it did — full transcript
promptthe exact instruction sent to the model
view full prompt
You are completing a coding task in one shot. Write complete files that satisfy the spec below. Tests (pytest) will be run against your files; you cannot run them yourself.
Reply with ONE JSON object and nothing else:
{"files": {"<relative path>": "<complete file content>", ...}}
Required deliverable files: calc.py
SPEC:
Create calc.py with exactly one public function:
evaluate(expr: str) -> float
Evaluate an arithmetic expression containing numbers (integers or decimals), the binary operators + - * /, unary minus, parentheses, and arbitrary whitespace. Normal precedence: * and / bind tighter than + and -; operators of equal precedence associate left to right. Division is true division. Examples: evaluate("2+3*4") == 14, evaluate("(2+3)*4") == 20, evaluate("2*-3") == -6.
You must parse the expression yourself: using eval() or exec() is forbidden and is checked by the test suite. Use only the Python standard library.
reply254 tokens
view raw reply
{"files": {"calc.py": "import re\nfrom shunting_yard import ShuntingYard\n\ndef evaluate(expr: str) -> float:\n # Define operator precedence\n precedence = {'+': 1, '-': 1, '*': 2, '/': 2}\n # Create a dictionary to map operators to their corresponding functions\n operators = {'+': lambda x, y: x + y, '-': lambda x, y: x - y, '*': lambda x, y: x * y, '/': lambda x, y: x / y}\n # Use shunting-yard parsing to convert infix notation to postfix\n postFix = ShuntingYard().parse(expr)\n # Evaluate the postfix expression\n stack = []\n for token in postFix:\n if token.isnumeric():\n stack.append(float(token))\n elif token == '-':\n stack.append(-stack.pop())\n else:\n operand2 = stack.pop()\n operand1 = stack.pop()\n result = operators[token](operand1, operand2)\n stack.append(result)\n return stack[0]"}}write_filecalc.py · 878 B
graded 40.00 passed, 1 failed
pytest output
==================================== ERRORS ====================================
________________________ ERROR collecting test_calc.py _________________________
ImportError while importing test module '/Users/richardblundell/repos/llmcoderlab/.lab/runs/2/llama3.2-3b/oneshot/calculator/s0/test_calc.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/importlib/__init__.py:88: in import_module
return _bootstrap._gcd_import(name[level:], package, level)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
test_calc.py:3: in <module>
from calc import evaluate
calc.py:2: in <module>
from shunting_yard import ShuntingYard
E ModuleNotFoundError: No module named 'shunting_yard'
=========================== short test summary info ============================
ERROR test_calc.py
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
1 error in 0.09s
03 what it wrote
1
files
23
lines
18
source lines
1
functions
0
classes
4
cyclomatic
4
max nesting
20.0
avg fn lines
stdlib imports: re, shunting_yard
| File | LOC | SLOC | Fns | Complexity | Depth | Imports |
|---|---|---|---|---|---|---|
| calc.py | 23 | 18 | 1 | 4 | 4 | re, shunting_yard |
calc.py · 23 lines · 878 B
import refrom shunting_yard import ShuntingYard def evaluate(expr: str) -> float: # Define operator precedence precedence = {'+': 1, '-': 1, '*': 2, '/': 2} # Create a dictionary to map operators to their corresponding functions operators = {'+': lambda x, y: x + y, '-': lambda x, y: x - y, '*': lambda x, y: x * y, '/': lambda x, y: x / y} # Use shunting-yard parsing to convert infix notation to postfix postFix = ShuntingYard().parse(expr) # Evaluate the postfix expression stack = [] for token in postFix: if token.isnumeric(): stack.append(float(token)) elif token == '-': stack.append(-stack.pop()) else: operand2 = stack.pop() operand1 = stack.pop() result = operators[token](operand1, operand2) stack.append(result) return stack[0]
04 how it was graded
1
model calls
0
invalid actions
0
self test runs
254
tokens out
—
tokens in
12.4s
wall time
agent actions: —
final pytest output
==================================== ERRORS ====================================
________________________ ERROR collecting test_calc.py _________________________
ImportError while importing test module '/Users/richardblundell/repos/llmcoderlab/.lab/runs/2/llama3.2-3b/oneshot/calculator/s0/test_calc.py'.
Hint: make sure your test modules/packages have valid Python names.
Traceback:
/opt/homebrew/Cellar/python@3.14/3.14.4/Frameworks/Python.framework/Versions/3.14/lib/python3.14/importlib/__init__.py:88: in import_module
return _bootstrap._gcd_import(name[level:], package, level)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
test_calc.py:3: in <module>
from calc import evaluate
calc.py:2: in <module>
from shunting_yard import ShuntingYard
E ModuleNotFoundError: No module named 'shunting_yard'
=========================== short test summary info ============================
ERROR test_calc.py
!!!!!!!!!!!!!!!!!!!! Interrupted: 1 error during collection !!!!!!!!!!!!!!!!!!!!
1 error in 0.09s