⚡️ Speed up method CohereObject.__repr__ by 29%

[codeflash-ai]

📄 29% (0.29x) speedup for CohereObject.__repr__ in src/cohere/manually_maintained/cohere_aws/response.py

⏱️ Runtime : 415 microseconds → 322 microseconds (best of 444 runs)

📝 Explanation and details

The optimization achieves a 28% speedup by eliminating inefficient string concatenation in the loop. The key changes are:

What was optimized:

1. Replaced string concatenation with list comprehension + join: Instead of repeatedly concatenating strings with contents += f'...' in a loop, the code now builds a list of formatted strings and joins them in a single operation.
2. Cached type name: type(self).__name__ is computed once and stored in type_name to avoid repeated lookups.
3. Used dict.items() instead of dict.keys(): Eliminates redundant dictionary lookups by getting both key and value in one iteration.

Why this is faster:

• String concatenation in Python creates new string objects each time (strings are immutable), leading to O(n²) behavior for n attributes
• ''.join() is highly optimized in CPython and performs the concatenation in O(n) time
• Avoiding repeated self.__dict__[k] lookups reduces dictionary access overhead
• Caching type(self).__name__ eliminates redundant method calls

Performance characteristics from tests:

• Small objects (1-10 attributes): Minor slowdown due to list creation overhead, but negligible in absolute terms
• Large objects (100+ attributes): Significant gains - up to 47.6% faster for objects with 1000 attributes, where the O(n²) vs O(n) difference becomes pronounced
• The optimization particularly shines when __repr__ is called on objects with many attributes, which is common in data-heavy applications

✅ Correctness verification report:

Test	Status
⚙️ Existing Unit Tests	🔘 None Found
🌀 Generated Regression Tests	✅ 75 Passed
⏪ Replay Tests	🔘 None Found
🔎 Concolic Coverage Tests	✅ 2 Passed
📊 Tests Coverage	100.0%

🌀 Generated Regression Tests and Runtime

import pytest
from cohere.manually_maintained.cohere_aws.response import CohereObject

# ------------------- Unit Tests -------------------

# 1. Basic Test Cases

def test_repr_empty_object():
    """
    Test __repr__ for an object with no attributes.
    Should show only the class name and empty contents.
    """
    obj = CohereObject()
    expected = "cohere.CohereObject {\n}"
    codeflash_output = obj.__repr__() # 1.24μs -> 1.91μs (35.0% slower)

def test_repr_single_attribute():
    """
    Test __repr__ for an object with a single attribute.
    """
    obj = CohereObject()
    obj.foo = 42
    expected = "cohere.CohereObject {\n\tfoo: 42\n}"
    codeflash_output = obj.__repr__() # 1.82μs -> 2.39μs (24.1% slower)

def test_repr_multiple_attributes():
    """
    Test __repr__ for an object with multiple attributes.
    """
    obj = CohereObject()
    obj.a = 1
    obj.b = 'bar'
    obj.c = [1,2,3]
    expected = "cohere.CohereObject {\n\ta: 1\n\tb: bar\n\tc: [1, 2, 3]\n}"
    codeflash_output = obj.__repr__() # 3.42μs -> 4.15μs (17.5% slower)

def test_repr_excludes_iterator():
    """
    Test that 'iterator' is excluded from __repr__ output.
    """
    obj = CohereObject()
    obj.iterator = "should not appear"
    obj.foo = "should appear"
    expected = "cohere.CohereObject {\n\tfoo: should appear\n}"
    codeflash_output = obj.__repr__() # 1.70μs -> 2.31μs (26.4% slower)

# 2. Edge Test Cases

def test_repr_attribute_with_newlines():
    """
    Test __repr__ for an attribute containing newlines.
    """
    obj = CohereObject()
    obj.text = "line1\nline2"
    expected = "cohere.CohereObject {\n\ttext: line1\nline2\n}"
    codeflash_output = obj.__repr__() # 1.67μs -> 2.20μs (24.1% slower)

def test_repr_attribute_is_none():
    """
    Test __repr__ for an attribute set to None.
    """
    obj = CohereObject()
    obj.val = None
    expected = "cohere.CohereObject {\n\tval: None\n}"
    codeflash_output = obj.__repr__() # 1.84μs -> 2.40μs (23.4% slower)

def test_repr_attribute_is_bool():
    """
    Test __repr__ for boolean attributes.
    """
    obj = CohereObject()
    obj.flag = True
    obj.other = False
    expected = "cohere.CohereObject {\n\tflag: True\n\tother: False\n}"
    codeflash_output = obj.__repr__() # 2.58μs -> 3.12μs (17.1% slower)

def test_repr_attribute_is_dict():
    """
    Test __repr__ for an attribute that is a dictionary.
    """
    obj = CohereObject()
    obj.mapping = {'x': 1, 'y': 2}
    expected = "cohere.CohereObject {\n\tmapping: {'x': 1, 'y': 2}\n}"
    codeflash_output = obj.__repr__() # 3.04μs -> 3.78μs (19.6% slower)

def test_repr_attribute_is_object():
    """
    Test __repr__ for an attribute that is another object.
    """
    other = CohereObject()
    other.foo = "bar"
    obj = CohereObject()
    obj.child = other
    # The __repr__ of child should be called
    expected = f"cohere.CohereObject {{\n\tchild: {other.__repr__()}\n}}" # 1.63μs -> 2.15μs (24.1% slower)
    codeflash_output = obj.__repr__() # 1.76μs -> 2.63μs (33.4% slower)

def test_repr_attribute_with_special_characters():
    """
    Test __repr__ for an attribute with special characters.
    """
    obj = CohereObject()
    obj.special = "tab:\t, newline:\n, unicode: ☃"
    expected = "cohere.CohereObject {\n\tspecial: tab:\t, newline:\n, unicode: ☃\n}"
    codeflash_output = obj.__repr__() # 1.97μs -> 2.49μs (20.9% slower)

def test_repr_attribute_with_empty_string():
    """
    Test __repr__ for an attribute with an empty string.
    """
    obj = CohereObject()
    obj.empty = ""
    expected = "cohere.CohereObject {\n\tempty: \n}"
    codeflash_output = obj.__repr__() # 1.53μs -> 2.00μs (23.3% slower)

def test_repr_attribute_with_zero():
    """
    Test __repr__ for an attribute with value zero.
    """
    obj = CohereObject()
    obj.zero = 0
    expected = "cohere.CohereObject {\n\tzero: 0\n}"
    codeflash_output = obj.__repr__() # 1.61μs -> 2.06μs (22.1% slower)

def test_repr_attribute_with_large_int():
    """
    Test __repr__ for an attribute with a large integer value.
    """
    obj = CohereObject()
    obj.large = 10**18
    expected = f"cohere.CohereObject {{\n\tlarge: {10**18}\n}}"
    codeflash_output = obj.__repr__() # 1.79μs -> 2.26μs (20.6% slower)

def test_repr_attribute_with_float():
    """
    Test __repr__ for an attribute with a float value.
    """
    obj = CohereObject()
    obj.number = 3.14159
    expected = "cohere.CohereObject {\n\tnumber: 3.14159\n}"
    codeflash_output = obj.__repr__() # 3.33μs -> 3.91μs (14.9% slower)

def test_repr_attribute_with_tuple():
    """
    Test __repr__ for an attribute that is a tuple.
    """
    obj = CohereObject()
    obj.tupled = (1, 'a', 3.14)
    expected = "cohere.CohereObject {\n\ttupled: (1, 'a', 3.14)\n}"
    codeflash_output = obj.__repr__() # 3.85μs -> 4.75μs (19.0% slower)

def test_repr_attribute_with_set():
    """
    Test __repr__ for an attribute that is a set.
    """
    obj = CohereObject()
    obj.s = {1, 2, 3}
    # Sets are unordered; check for presence of all elements
    codeflash_output = obj.__repr__(); output = codeflash_output # 3.30μs -> 3.90μs (15.6% slower)
    for v in ['1', '2', '3']:
        pass

def test_repr_attribute_with_bytes():
    """
    Test __repr__ for an attribute that is bytes.
    """
    obj = CohereObject()
    obj.data = b'abc'
    expected = "cohere.CohereObject {\n\tdata: b'abc'\n}"
    codeflash_output = obj.__repr__() # 1.96μs -> 2.46μs (20.1% slower)

# 3. Large Scale Test Cases

def test_repr_many_attributes():
    """
    Test __repr__ for an object with a large number of attributes.
    """
    obj = CohereObject()
    for i in range(1000):
        setattr(obj, f'attr{i}', i)
    # Build expected output
    contents = ''.join([f'\tattr{i}: {i}\n' for i in range(1000)])
    expected = f'cohere.CohereObject {{\n{contents}}}'
    codeflash_output = obj.__repr__() # 154μs -> 104μs (47.6% faster)

def test_repr_large_list_attribute():
    """
    Test __repr__ for an attribute that is a large list.
    """
    obj = CohereObject()
    large_list = list(range(1000))
    obj.biglist = large_list
    expected = f"cohere.CohereObject {{\n\tbiglist: {large_list}\n}}"
    codeflash_output = obj.__repr__() # 27.1μs -> 30.4μs (10.6% slower)

def test_repr_large_nested_object():
    """
    Test __repr__ for an object containing another object with many attributes.
    """
    child = CohereObject()
    for i in range(100):
        setattr(child, f'x{i}', i)
    obj = CohereObject()
    obj.child = child
    expected = f"cohere.CohereObject {{\n\tchild: {child.__repr__()}\n}}" # 18.6μs -> 14.1μs (32.2% faster)
    codeflash_output = obj.__repr__() # 17.3μs -> 13.9μs (24.5% faster)

def test_repr_performance_large_object():
    """
    Test __repr__ performance for an object with many attributes.
    Ensures the function completes in a reasonable time.
    """
    import time
    obj = CohereObject()
    for i in range(999):
        setattr(obj, f'a{i}', i)
    start = time.time()
    codeflash_output = obj.__repr__(); result = codeflash_output # 156μs -> 106μs (46.8% faster)
    end = time.time()
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
import pytest  # used for our unit tests
from cohere.manually_maintained.cohere_aws.response import CohereObject

# unit tests

# ---------------- BASIC TEST CASES ----------------

def test_repr_empty_object():
    """Test __repr__ with an object that has no attributes."""
    obj = CohereObject()
    expected = 'cohere.CohereObject {\n}'

def test_repr_single_attribute():
    """Test __repr__ with a single attribute."""
    obj = CohereObject()
    obj.foo = 'bar'
    expected = 'cohere.CohereObject {\n\tfoo: bar\n}'

def test_repr_multiple_attributes():
    """Test __repr__ with multiple attributes."""
    obj = CohereObject()
    obj.a = 1
    obj.b = 'test'
    obj.c = [1, 2, 3]
    expected = 'cohere.CohereObject {\n\ta: 1\n\tb: test\n\tc: [1, 2, 3]\n}'

def test_repr_attribute_types():
    """Test __repr__ with attributes of different types."""
    obj = CohereObject()
    obj.int_attr = 42
    obj.float_attr = 3.14
    obj.bool_attr = True
    obj.none_attr = None
    expected = (
        'cohere.CohereObject {\n'
        '\tint_attr: 42\n'
        '\tfloat_attr: 3.14\n'
        '\tbool_attr: True\n'
        '\tnone_attr: None\n'
        '}'
    )

# ---------------- EDGE TEST CASES ----------------

def test_repr_exclude_iterator():
    """Test that 'iterator' attribute is excluded from __repr__ output."""
    obj = CohereObject()
    obj.iterator = 'should not appear'
    obj.visible = 'should appear'
    expected = 'cohere.CohereObject {\n\tvisible: should appear\n}'

def test_repr_attribute_with_newline():
    """Test __repr__ with attribute values containing newlines."""
    obj = CohereObject()
    obj.text = "line1\nline2"
    expected = 'cohere.CohereObject {\n\ttext: line1\nline2\n}'

def test_repr_attribute_with_special_characters():
    """Test __repr__ with attribute values containing special characters."""
    obj = CohereObject()
    obj.special = "\t\n\r!@#$%^&*()"
    expected = f'cohere.CohereObject {{\n\tspecial: {obj.special}\n}}'

def test_repr_attribute_with_unicode():
    """Test __repr__ with attribute values containing unicode characters."""
    obj = CohereObject()
    obj.unicode = "😀🚀"
    expected = 'cohere.CohereObject {\n\tunicode: 😀🚀\n}'

def test_repr_attribute_with_empty_string():
    """Test __repr__ with attribute value as empty string."""
    obj = CohereObject()
    obj.empty = ""
    expected = 'cohere.CohereObject {\n\tempty: \n}'

def test_repr_attribute_with_empty_list_dict():
    """Test __repr__ with attribute values as empty list and dict."""
    obj = CohereObject()
    obj.empty_list = []
    obj.empty_dict = {}
    expected = 'cohere.CohereObject {\n\tempty_list: []\n\tempty_dict: {}\n}'

def test_repr_attribute_with_nested_object():
    """Test __repr__ with attribute value as another CohereObject."""
    nested = CohereObject()
    nested.x = 99
    obj = CohereObject()
    obj.nested = nested
    # The repr of nested will be its own repr string
    expected = f'cohere.CohereObject {{\n\tnested: {repr(nested)}\n}}'

def test_repr_attribute_with_tuple_set():
    """Test __repr__ with tuple and set attributes."""
    obj = CohereObject()
    obj.tuple_attr = (1, 2)
    obj.set_attr = {3, 4}
    # Set order is not guaranteed, so compare with both possible outputs
    possible = [
        'cohere.CohereObject {\n\ttuple_attr: (1, 2)\n\tset_attr: {3, 4}\n}',
        'cohere.CohereObject {\n\ttuple_attr: (1, 2)\n\tset_attr: {4, 3}\n}',
    ]

def test_repr_attribute_with_long_string():
    """Test __repr__ with very long string attribute."""
    obj = CohereObject()
    long_str = "x" * 500
    obj.long = long_str
    expected = f'cohere.CohereObject {{\n\tlong: {long_str}\n}}'

# ---------------- LARGE SCALE TEST CASES ----------------

def test_repr_many_attributes():
    """Test __repr__ with a large number of attributes."""
    obj = CohereObject()
    n = 999  # Under 1000 as per instructions
    for i in range(n):
        setattr(obj, f'attr_{i}', i)
    # Build expected string
    contents = ''.join([f'\tattr_{i}: {i}\n' for i in range(n)])
    expected = f'cohere.CohereObject {{\n{contents}}}'

def test_repr_large_list_attribute():
    """Test __repr__ with an attribute that is a large list."""
    obj = CohereObject()
    large_list = list(range(1000))
    obj.biglist = large_list
    expected = f'cohere.CohereObject {{\n\tbiglist: {large_list}\n}}'

def test_repr_large_dict_attribute():
    """Test __repr__ with an attribute that is a large dict."""
    obj = CohereObject()
    large_dict = {str(i): i for i in range(999)}
    obj.bigdict = large_dict
    expected = f'cohere.CohereObject {{\n\tbigdict: {large_dict}\n}}'

def test_repr_large_nested_objects():
    """Test __repr__ with nested CohereObjects up to 10 levels deep."""
    obj = CohereObject()
    current = obj
    for i in range(10):
        nested = CohereObject()
        setattr(current, f'level_{i}', nested)
        current = nested
    # Only test that it runs and contains the correct nesting
    result = repr(obj)
    # Should contain 10 levels of nesting
    for i in range(10):
        pass

def test_repr_performance_large_attributes():
    """Test __repr__ with many attributes to ensure reasonable performance."""
    import time
    obj = CohereObject()
    for i in range(999):
        setattr(obj, f'attr_{i}', 'x' * 100)
    start = time.time()
    repr_str = repr(obj)
    elapsed = time.time() - start
# codeflash_output is used to check that the output of the original code is the same as that of the optimized code.
#------------------------------------------------
from cohere.manually_maintained.cohere_aws.response import CohereObject

def test_CohereObject___repr__():
    CohereObject.__repr__(CohereObject())

🔎 Concolic Coverage Tests and Runtime

Test File::Test Function	Original ⏱️	Optimized ⏱️	Speedup
codeflash_concolic_yxtehl4j/tmp8csm7co8/test_concolic_coverage.py::test_CohereObject___repr__	1.40μs	2.16μs	-35.0%⚠️

To edit these changes git checkout codeflash/optimize-CohereObject.__repr__-mgzklfx3 and push.