⚡️ Speed up method bittrade.parse_trading_limits by 124%

[codeflash-ai]

📄 124% (1.24x) speedup for bittrade.parse_trading_limits in python/ccxt/bittrade.py

⏱️ Runtime : 103 microseconds → 46.3 microseconds (best of 122 runs)

📝 Explanation and details

The optimization achieves a 123% speedup by eliminating redundant dictionary lookups and method calls in the safe_number function, which is heavily used in trading limit parsing.

Key Optimizations:

1. Direct Dictionary Access: Replaced the indirect self.safe_string(obj, key) call with direct obj.get(key, None), eliminating an extra method call and string conversion overhead when the value is None.

2. Early Return Pattern: Added explicit None check with early return, avoiding unnecessary string conversion and number parsing when values don't exist in the dictionary.

3. Streamlined Exception Handling: Replaced the multi-step safe_string → parse_number chain with direct self.number(value) call wrapped in try-catch, reducing method call overhead.

4. Reduced Variable Assignments: In parse_trading_limits, extracted safe_number calls into variables to prevent redundant dictionary access during object construction.

Why This Works:
Python dictionary .get() is highly optimized at the C level, while the original safe_string implementation involved additional method calls, attribute lookups, and string conversions even for missing keys. The optimization eliminates ~68% of the original function's time spent in safe_string calls.

Impact on Workloads:
The test results show consistent 50-180% improvements across all scenarios, with the biggest gains when processing dictionaries with missing keys (169% faster for empty dicts). This is particularly beneficial for cryptocurrency exchange APIs where trading limits are parsed frequently with sparse or incomplete data, making this optimization valuable for high-frequency trading applications.

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 63 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	🔘 None Found
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import pytest
from ccxt.bittrade import bittrade

# --- Unit tests for bittrade.parse_trading_limits ---

@pytest.fixture
def parser():
    # Provide a fresh instance for each test
    return bittrade()

# ---------------------
# 1. Basic Test Cases
# ---------------------




def test_basic_with_extra_fields(parser):
    # Input with extra fields (should ignore them)
    limits = {
        "limit-order-must-greater-than": 10,
        "limit-order-must-less-than": 20,
        "irrelevant-field": 999,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 5.00μs -> 2.19μs (128% faster)
    # The extra field should not affect the result

# ---------------------
# 2. Edge Test Cases
# ---------------------

def test_edge_missing_min(parser):
    # Missing min field
    limits = {
        "limit-order-must-less-than": 100,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 5.30μs -> 2.11μs (151% faster)

def test_edge_missing_max(parser):
    # Missing max field
    limits = {
        "limit-order-must-greater-than": 5,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 5.09μs -> 2.10μs (142% faster)

def test_edge_missing_both(parser):
    # Both fields missing
    limits = {
        "some-other-key": 123,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.00μs -> 1.49μs (169% faster)

def test_edge_null_values(parser):
    # Both fields are None
    limits = {
        "limit-order-must-greater-than": None,
        "limit-order-must-less-than": None,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 3.43μs -> 1.53μs (124% faster)

def test_edge_non_numeric_values(parser):
    # Both fields are non-numeric strings
    limits = {
        "limit-order-must-greater-than": "abc",
        "limit-order-must-less-than": "def",
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 6.57μs -> 4.34μs (51.4% faster)

def test_edge_zero_and_negative(parser):
    # Zero and negative numbers
    limits = {
        "limit-order-must-greater-than": 0,
        "limit-order-must-less-than": -100,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 5.12μs -> 2.10μs (143% faster)

def test_edge_min_greater_than_max(parser):
    # min > max (should not error, just reflect input)
    limits = {
        "limit-order-must-greater-than": 100,
        "limit-order-must-less-than": 10,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.90μs -> 2.11μs (132% faster)

def test_edge_min_equals_max(parser):
    # min == max
    limits = {
        "limit-order-must-greater-than": 42,
        "limit-order-must-less-than": 42,
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.83μs -> 2.13μs (127% faster)

def test_edge_large_float_string(parser):
    # Very large float as string
    limits = {
        "limit-order-must-greater-than": "1e10",
        "limit-order-must-less-than": "2e10",
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.72μs -> 2.59μs (82.5% faster)

def test_edge_empty_dict(parser):
    # Empty dict input
    limits = {}
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 3.94μs -> 1.47μs (169% faster)

def test_edge_symbol_and_params(parser):
    # Symbol and params are ignored
    limits = {
        "limit-order-must-greater-than": 7,
        "limit-order-must-less-than": 77,
    }
    codeflash_output = parser.parse_trading_limits(limits, symbol="BTC/USD", params={"foo": "bar"}); result = codeflash_output # 5.21μs -> 2.46μs (111% faster)

def test_edge_info_field(parser):
    # The info field should be exactly the original input
    limits = {
        "limit-order-must-greater-than": 7,
        "limit-order-must-less-than": 77,
        "random-key": "random-value"
    }
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.91μs -> 2.03μs (142% faster)

# ---------------------
# 3. Large Scale Test Cases
# ---------------------

def test_large_scale_many_extra_fields(parser):
    # Input dict with 1000 unrelated fields and correct fields
    limits = {f"extra{i}": i for i in range(1000)}
    limits["limit-order-must-greater-than"] = 123
    limits["limit-order-must-less-than"] = 456
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 5.03μs -> 2.25μs (124% faster)

def test_large_scale_stringified_numbers(parser):
    # Input dict with numeric strings for 1000 unrelated fields, and correct fields
    limits = {f"extra{i}": str(i) for i in range(1000)}
    limits["limit-order-must-greater-than"] = "789"
    limits["limit-order-must-less-than"] = "987"
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.75μs -> 2.64μs (80.2% faster)

def test_large_scale_missing_fields(parser):
    # Input dict with 1000 unrelated fields, but missing min/max
    limits = {f"extra{i}": i for i in range(1000)}
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 4.26μs -> 1.52μs (180% faster)

def test_large_scale_all_none(parser):
    # Input dict with 1000 unrelated fields, plus min/max as None
    limits = {f"extra{i}": None for i in range(1000)}
    limits["limit-order-must-greater-than"] = None
    limits["limit-order-must-less-than"] = None
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 3.64μs -> 1.59μs (128% faster)

def test_large_scale_all_non_numeric(parser):
    # Input dict with 1000 unrelated fields, min/max as non-numeric
    limits = {f"extra{i}": "not-a-number" for i in range(1000)}
    limits["limit-order-must-greater-than"] = "NaN"
    limits["limit-order-must-less-than"] = "Infinity"
    codeflash_output = parser.parse_trading_limits(limits); result = codeflash_output # 5.00μs -> 2.83μs (77.0% faster)
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.

import pytest
from ccxt.bittrade import bittrade


# function to test (simplified for unit testing, as per ccxt/bittrade.py)
class Bittrade:
    def parse_number(self, value, default=None):
        try:
            if value is None:
                return default
            return float(value)
        except Exception:
            return default

    def safe_number(self, obj, key, default=None):
        value = obj.get(key)
        return self.parse_number(value, default)

    def parse_trading_limits(self, limits, symbol=None, params={}):
        return {
            'info': limits,
            'limits': {
                'amount': {
                    'min': self.safe_number(limits, 'limit-order-must-greater-than'),
                    'max': self.safe_number(limits, 'limit-order-must-less-than'),
                },
            },
        }
from ccxt.bittrade import bittrade

# 1. Basic Test Cases

To edit these changes git checkout codeflash/optimize-bittrade.parse_trading_limits-mhx0ktfi and push.