From 74b9105a5bacd88b040178ab8b2004126ea9de37 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 03:54:21 +0000
Subject: [PATCH 01/13] Initial plan


From d6dd79dd90a41c69d1230b1bf4a7a975e28d3478 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:00:50 +0000
Subject: [PATCH 02/13] Make numpy import lazy in prometheus_connect.py

- Remove numpy import from module level in prometheus_connect.py
- Add lazy import of numpy inside get_metric_aggregation method
- Add tests to verify PrometheusConnect can be imported without loading pandas/matplotlib/numpy
- All mocked network tests pass successfully

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 prometheus_api_client/prometheus_connect.py |   3 +-
 tests/test_lazy_imports.py                  | 100 ++++++++++++++++++++
 2 files changed, 102 insertions(+), 1 deletion(-)
 create mode 100644 tests/test_lazy_imports.py

diff --git a/prometheus_api_client/prometheus_connect.py b/prometheus_api_client/prometheus_connect.py
index cd24cb4..0149930 100644
--- a/prometheus_api_client/prometheus_connect.py
+++ b/prometheus_api_client/prometheus_connect.py
@@ -4,7 +4,6 @@
 import os
 import json
 import logging
-import numpy
 from datetime import datetime, timedelta
 import requests
 from requests.adapters import HTTPAdapter
@@ -569,6 +568,8 @@ def get_metric_aggregation(
                 'max': 6.009373
              }
         """
+        import numpy
+        
         if not isinstance(operations, list):
             raise TypeError("Operations can be only of type list")
         if len(operations) == 0:
diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
new file mode 100644
index 0000000..c0fce18
--- /dev/null
+++ b/tests/test_lazy_imports.py
@@ -0,0 +1,100 @@
+"""Test lazy imports to ensure pandas/matplotlib are not loaded unnecessarily."""
+import unittest
+import sys
+import importlib
+
+
+class TestLazyImports(unittest.TestCase):
+    """Test that PrometheusConnect can be imported without loading heavy dependencies."""
+
+    def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
+        """Test that importing PrometheusConnect doesn't load pandas, matplotlib, or numpy."""
+        # Remove any previously loaded prometheus_api_client modules
+        modules_to_remove = [
+            key for key in sys.modules.keys()
+            if key.startswith('prometheus_api_client')
+        ]
+        for module in modules_to_remove:
+            del sys.modules[module]
+        
+        # Also remove numpy, pandas, matplotlib if they were loaded
+        for heavy_module in ['numpy', 'pandas', 'matplotlib']:
+            modules_to_remove = [
+                key for key in sys.modules.keys()
+                if key == heavy_module or key.startswith(heavy_module + '.')
+            ]
+            for module in modules_to_remove:
+                del sys.modules[module]
+        
+        # Import PrometheusConnect
+        from prometheus_api_client import PrometheusConnect
+        
+        # Check that pandas, matplotlib, and numpy are not loaded
+        loaded_modules = sys.modules.keys()
+        pandas_loaded = any('pandas' in m for m in loaded_modules)
+        matplotlib_loaded = any('matplotlib' in m for m in loaded_modules)
+        numpy_loaded = any('numpy' in m for m in loaded_modules)
+        
+        self.assertFalse(pandas_loaded, "pandas should not be loaded when importing PrometheusConnect")
+        self.assertFalse(matplotlib_loaded, "matplotlib should not be loaded when importing PrometheusConnect")
+        self.assertFalse(numpy_loaded, "numpy should not be loaded when importing PrometheusConnect")
+        
+    def test_prometheus_connect_instantiation_without_numpy(self):
+        """Test that PrometheusConnect can be instantiated without loading numpy."""
+        # Remove any previously loaded prometheus_api_client modules
+        modules_to_remove = [
+            key for key in sys.modules.keys()
+            if key.startswith('prometheus_api_client')
+        ]
+        for module in modules_to_remove:
+            del sys.modules[module]
+        
+        # Also remove numpy if it was loaded
+        modules_to_remove = [
+            key for key in sys.modules.keys()
+            if key == 'numpy' or key.startswith('numpy.')
+        ]
+        for module in modules_to_remove:
+            del sys.modules[module]
+        
+        # Import and instantiate PrometheusConnect
+        from prometheus_api_client import PrometheusConnect
+        pc = PrometheusConnect(url='http://test.local:9090')
+        
+        # Check that numpy is still not loaded after instantiation
+        loaded_modules = sys.modules.keys()
+        numpy_loaded = any('numpy' in m for m in loaded_modules)
+        
+        self.assertFalse(numpy_loaded, "numpy should not be loaded when instantiating PrometheusConnect")
+        self.assertIsNotNone(pc, "PrometheusConnect should be instantiated successfully")
+
+    def test_metric_import_loads_pandas(self):
+        """Test that importing Metric does load pandas (expected behavior)."""
+        # Remove any previously loaded prometheus_api_client modules
+        modules_to_remove = [
+            key for key in sys.modules.keys()
+            if key.startswith('prometheus_api_client')
+        ]
+        for module in modules_to_remove:
+            del sys.modules[module]
+        
+        # Also remove pandas if it was loaded
+        modules_to_remove = [
+            key for key in sys.modules.keys()
+            if key == 'pandas' or key.startswith('pandas.')
+        ]
+        for module in modules_to_remove:
+            del sys.modules[module]
+        
+        # Import Metric
+        from prometheus_api_client import Metric
+        
+        # Check that pandas is loaded (this is expected for Metric)
+        loaded_modules = sys.modules.keys()
+        pandas_loaded = any('pandas' in m for m in loaded_modules)
+        
+        self.assertTrue(pandas_loaded, "pandas should be loaded when importing Metric")
+
+
+if __name__ == '__main__':
+    unittest.main()

From 2447357474c0e2e0f78148b573674ffdf0f81a33 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:03:13 +0000
Subject: [PATCH 03/13] Add optional dependencies support via extras_require

- Create requirements-core.txt with only core dependencies (requests, dateparser)
- Update setup.py to support extras_require with 'dataframe', 'numpy', 'plot', and 'all' options
- Update README.md with installation instructions for optional dependencies
- Users can now install minimal version without pandas/matplotlib/numpy for reduced memory footprint

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 README.md             | 12 ++++++++++++
 requirements-core.txt |  2 ++
 setup.py              | 10 ++++++++--
 3 files changed, 22 insertions(+), 2 deletions(-)
 create mode 100644 requirements-core.txt

diff --git a/README.md b/README.md
index 97c5111..92b185a 100644
--- a/README.md
+++ b/README.md
@@ -11,6 +11,18 @@ To install the latest release:
 
 `pip install prometheus-api-client`
 
+To install with all optional dependencies (pandas, numpy, matplotlib):
+
+`pip install prometheus-api-client[all]`
+
+**Note:** Starting from version 0.6.0, pandas, numpy, and matplotlib are optional dependencies. 
+If you only need `PrometheusConnect` without DataFrame support or plotting capabilities, you can install the minimal version which significantly reduces memory footprint and installation time, especially on Alpine-based Docker images.
+
+To install only specific extras:
+- For DataFrame support: `pip install prometheus-api-client[dataframe]`
+- For numpy support: `pip install prometheus-api-client[numpy]`
+- For plotting support: `pip install prometheus-api-client[plot]`
+
 To install directly from this branch:
 
 `pip install https://github.com/4n4nd/prometheus-api-client-python/zipball/master`
diff --git a/requirements-core.txt b/requirements-core.txt
new file mode 100644
index 0000000..bbfd6bf
--- /dev/null
+++ b/requirements-core.txt
@@ -0,0 +1,2 @@
+requests
+dateparser
diff --git a/setup.py b/setup.py
index 4796b1a..4a6c1ab 100644
--- a/setup.py
+++ b/setup.py
@@ -7,8 +7,8 @@
 
 
 def get_install_requires():
-    """Get requirements from requirements.txt."""
-    with open("requirements.txt", "r") as requirements_file:
+    """Get core requirements from requirements-core.txt."""
+    with open("requirements-core.txt", "r") as requirements_file:
         res = requirements_file.readlines()
         return [req.split(" ", maxsplit=1)[0] for req in res if req]
 
@@ -36,6 +36,12 @@ def get_version():
     long_description_content_type="text/markdown",
     url="https://github.com/4n4nd/prometheus-api-client-python",
     install_requires=get_install_requires(),
+    extras_require={
+        "dataframe": ["pandas>=1.4.0"],
+        "numpy": ["numpy"],
+        "plot": ["matplotlib"],
+        "all": ["pandas>=1.4.0", "numpy", "matplotlib"],
+    },
     packages=setuptools.find_packages(),
     package_data={"prometheus-api-client": ["py.typed"]},
     tests_require=["httmock"],

From 74f87727d6bebf09a48ed8deee22d20b1d2501c5 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:06:24 +0000
Subject: [PATCH 04/13] Fix test module detection logic to avoid false
 positives

- Use exact module name matching instead of substring matching
- Check for 'modulename' or 'modulename.*' pattern to avoid false positives
- Prevents incorrect detection of modules with similar names

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 tests/test_lazy_imports.py | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
index c0fce18..295063f 100644
--- a/tests/test_lazy_imports.py
+++ b/tests/test_lazy_imports.py
@@ -31,9 +31,9 @@ def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
         
         # Check that pandas, matplotlib, and numpy are not loaded
         loaded_modules = sys.modules.keys()
-        pandas_loaded = any('pandas' in m for m in loaded_modules)
-        matplotlib_loaded = any('matplotlib' in m for m in loaded_modules)
-        numpy_loaded = any('numpy' in m for m in loaded_modules)
+        pandas_loaded = any(m == 'pandas' or m.startswith('pandas.') for m in loaded_modules)
+        matplotlib_loaded = any(m == 'matplotlib' or m.startswith('matplotlib.') for m in loaded_modules)
+        numpy_loaded = any(m == 'numpy' or m.startswith('numpy.') for m in loaded_modules)
         
         self.assertFalse(pandas_loaded, "pandas should not be loaded when importing PrometheusConnect")
         self.assertFalse(matplotlib_loaded, "matplotlib should not be loaded when importing PrometheusConnect")
@@ -63,7 +63,7 @@ def test_prometheus_connect_instantiation_without_numpy(self):
         
         # Check that numpy is still not loaded after instantiation
         loaded_modules = sys.modules.keys()
-        numpy_loaded = any('numpy' in m for m in loaded_modules)
+        numpy_loaded = any(m == 'numpy' or m.startswith('numpy.') for m in loaded_modules)
         
         self.assertFalse(numpy_loaded, "numpy should not be loaded when instantiating PrometheusConnect")
         self.assertIsNotNone(pc, "PrometheusConnect should be instantiated successfully")
@@ -91,7 +91,7 @@ def test_metric_import_loads_pandas(self):
         
         # Check that pandas is loaded (this is expected for Metric)
         loaded_modules = sys.modules.keys()
-        pandas_loaded = any('pandas' in m for m in loaded_modules)
+        pandas_loaded = any(m == 'pandas' or m.startswith('pandas.') for m in loaded_modules)
         
         self.assertTrue(pandas_loaded, "pandas should be loaded when importing Metric")
 

From 33e0289a820066aea2e0a9b4be9b2c17e873e553 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:08:18 +0000
Subject: [PATCH 05/13] Refactor test code to reduce duplication

- Extract module removal logic into _remove_modules() helper method
- Extract module checking logic into _is_module_loaded() helper method
- Improve code maintainability and readability

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 tests/test_lazy_imports.py | 97 +++++++++++++++-----------------------
 1 file changed, 39 insertions(+), 58 deletions(-)

diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
index 295063f..7bf9c2b 100644
--- a/tests/test_lazy_imports.py
+++ b/tests/test_lazy_imports.py
@@ -7,93 +7,74 @@
 class TestLazyImports(unittest.TestCase):
     """Test that PrometheusConnect can be imported without loading heavy dependencies."""
 
-    def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
-        """Test that importing PrometheusConnect doesn't load pandas, matplotlib, or numpy."""
-        # Remove any previously loaded prometheus_api_client modules
-        modules_to_remove = [
-            key for key in sys.modules.keys()
-            if key.startswith('prometheus_api_client')
-        ]
-        for module in modules_to_remove:
-            del sys.modules[module]
+    @staticmethod
+    def _remove_modules(module_names):
+        """Remove specified modules and their submodules from sys.modules.
         
-        # Also remove numpy, pandas, matplotlib if they were loaded
-        for heavy_module in ['numpy', 'pandas', 'matplotlib']:
+        Args:
+            module_names: List of module names to remove
+        """
+        for module_name in module_names:
             modules_to_remove = [
                 key for key in sys.modules.keys()
-                if key == heavy_module or key.startswith(heavy_module + '.')
+                if key == module_name or key.startswith(module_name + '.')
             ]
             for module in modules_to_remove:
                 del sys.modules[module]
+    
+    @staticmethod
+    def _is_module_loaded(module_name):
+        """Check if a module is loaded in sys.modules.
+        
+        Args:
+            module_name: Name of the module to check
+            
+        Returns:
+            bool: True if module is loaded, False otherwise
+        """
+        return any(m == module_name or m.startswith(module_name + '.') for m in sys.modules.keys())
+
+    def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
+        """Test that importing PrometheusConnect doesn't load pandas, matplotlib, or numpy."""
+        # Remove any previously loaded modules
+        self._remove_modules(['prometheus_api_client', 'numpy', 'pandas', 'matplotlib'])
         
         # Import PrometheusConnect
         from prometheus_api_client import PrometheusConnect
         
         # Check that pandas, matplotlib, and numpy are not loaded
-        loaded_modules = sys.modules.keys()
-        pandas_loaded = any(m == 'pandas' or m.startswith('pandas.') for m in loaded_modules)
-        matplotlib_loaded = any(m == 'matplotlib' or m.startswith('matplotlib.') for m in loaded_modules)
-        numpy_loaded = any(m == 'numpy' or m.startswith('numpy.') for m in loaded_modules)
-        
-        self.assertFalse(pandas_loaded, "pandas should not be loaded when importing PrometheusConnect")
-        self.assertFalse(matplotlib_loaded, "matplotlib should not be loaded when importing PrometheusConnect")
-        self.assertFalse(numpy_loaded, "numpy should not be loaded when importing PrometheusConnect")
+        self.assertFalse(self._is_module_loaded('pandas'), 
+                        "pandas should not be loaded when importing PrometheusConnect")
+        self.assertFalse(self._is_module_loaded('matplotlib'), 
+                        "matplotlib should not be loaded when importing PrometheusConnect")
+        self.assertFalse(self._is_module_loaded('numpy'), 
+                        "numpy should not be loaded when importing PrometheusConnect")
         
     def test_prometheus_connect_instantiation_without_numpy(self):
         """Test that PrometheusConnect can be instantiated without loading numpy."""
-        # Remove any previously loaded prometheus_api_client modules
-        modules_to_remove = [
-            key for key in sys.modules.keys()
-            if key.startswith('prometheus_api_client')
-        ]
-        for module in modules_to_remove:
-            del sys.modules[module]
-        
-        # Also remove numpy if it was loaded
-        modules_to_remove = [
-            key for key in sys.modules.keys()
-            if key == 'numpy' or key.startswith('numpy.')
-        ]
-        for module in modules_to_remove:
-            del sys.modules[module]
+        # Remove any previously loaded modules
+        self._remove_modules(['prometheus_api_client', 'numpy'])
         
         # Import and instantiate PrometheusConnect
         from prometheus_api_client import PrometheusConnect
         pc = PrometheusConnect(url='http://test.local:9090')
         
         # Check that numpy is still not loaded after instantiation
-        loaded_modules = sys.modules.keys()
-        numpy_loaded = any(m == 'numpy' or m.startswith('numpy.') for m in loaded_modules)
-        
-        self.assertFalse(numpy_loaded, "numpy should not be loaded when instantiating PrometheusConnect")
+        self.assertFalse(self._is_module_loaded('numpy'), 
+                        "numpy should not be loaded when instantiating PrometheusConnect")
         self.assertIsNotNone(pc, "PrometheusConnect should be instantiated successfully")
 
     def test_metric_import_loads_pandas(self):
         """Test that importing Metric does load pandas (expected behavior)."""
-        # Remove any previously loaded prometheus_api_client modules
-        modules_to_remove = [
-            key for key in sys.modules.keys()
-            if key.startswith('prometheus_api_client')
-        ]
-        for module in modules_to_remove:
-            del sys.modules[module]
-        
-        # Also remove pandas if it was loaded
-        modules_to_remove = [
-            key for key in sys.modules.keys()
-            if key == 'pandas' or key.startswith('pandas.')
-        ]
-        for module in modules_to_remove:
-            del sys.modules[module]
+        # Remove any previously loaded modules
+        self._remove_modules(['prometheus_api_client', 'pandas'])
         
         # Import Metric
         from prometheus_api_client import Metric
         
         # Check that pandas is loaded (this is expected for Metric)
-        loaded_modules = sys.modules.keys()
-        pandas_loaded = any(m == 'pandas' or m.startswith('pandas.') for m in loaded_modules)
-        
-        self.assertTrue(pandas_loaded, "pandas should be loaded when importing Metric")
+        self.assertTrue(self._is_module_loaded('pandas'), 
+                       "pandas should be loaded when importing Metric")
 
 
 if __name__ == '__main__':

From 7832b91ea887212aaf30131f97aec00a1deefc32 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:17:24 +0000
Subject: [PATCH 06/13] Bump version to 0.7.0 for new release

- Version 0.6.0 is already released
- Increment to 0.7.0 for this new feature release with optional dependencies

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 prometheus_api_client/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/prometheus_api_client/__init__.py b/prometheus_api_client/__init__.py
index 2fbd114..dd72b49 100644
--- a/prometheus_api_client/__init__.py
+++ b/prometheus_api_client/__init__.py
@@ -1,7 +1,7 @@
 """A collection of tools to collect and manipulate prometheus metrics."""
 
 __title__ = "prometheus-connect"
-__version__ = "0.6.0"
+__version__ = "0.7.0"
 
 from .exceptions import PrometheusApiClientException, MetricValueConversionError
 def __getattr__(name):

From b7f4b1e592a5d073023122b7717ba07b18daa9fc Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:24:31 +0000
Subject: [PATCH 07/13] Update README.md to reflect version 0.7.0

- Changed version reference from 0.6.0 to 0.7.0 in the optional dependencies note

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 README.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 92b185a..d7ea10b 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,7 @@ To install with all optional dependencies (pandas, numpy, matplotlib):
 
 `pip install prometheus-api-client[all]`
 
-**Note:** Starting from version 0.6.0, pandas, numpy, and matplotlib are optional dependencies. 
+**Note:** Starting from version 0.7.0, pandas, numpy, and matplotlib are optional dependencies. 
 If you only need `PrometheusConnect` without DataFrame support or plotting capabilities, you can install the minimal version which significantly reduces memory footprint and installation time, especially on Alpine-based Docker images.
 
 To install only specific extras:

From 08a7642b011e72591aeb5a6368e7ce156698e44c Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 04:57:22 +0000
Subject: [PATCH 08/13] Keep pandas as a core dependency

- Moved pandas>=1.4.0 from extras_require back to core requirements
- Updated README.md to reflect that pandas is a core dependency
- Removed 'dataframe' extra (no longer needed)
- NumPy remains optional with lazy loading
- All tests pass (46/46 relevant tests, same 9 pre-existing failures)

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 README.md             | 7 +++----
 requirements-core.txt | 1 +
 setup.py              | 3 +--
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index d7ea10b..da6c727 100644
--- a/README.md
+++ b/README.md
@@ -11,15 +11,14 @@ To install the latest release:
 
 `pip install prometheus-api-client`
 
-To install with all optional dependencies (pandas, numpy, matplotlib):
+To install with all optional dependencies (numpy, matplotlib):
 
 `pip install prometheus-api-client[all]`
 
-**Note:** Starting from version 0.7.0, pandas, numpy, and matplotlib are optional dependencies. 
-If you only need `PrometheusConnect` without DataFrame support or plotting capabilities, you can install the minimal version which significantly reduces memory footprint and installation time, especially on Alpine-based Docker images.
+**Note:** Starting from version 0.7.0, numpy and matplotlib are optional dependencies. Pandas is included as a core dependency.
+The lazy import mechanism ensures that `PrometheusConnect` can be imported without loading numpy until `get_metric_aggregation()` is called, which reduces initial memory footprint.
 
 To install only specific extras:
-- For DataFrame support: `pip install prometheus-api-client[dataframe]`
 - For numpy support: `pip install prometheus-api-client[numpy]`
 - For plotting support: `pip install prometheus-api-client[plot]`
 
diff --git a/requirements-core.txt b/requirements-core.txt
index bbfd6bf..cc00aef 100644
--- a/requirements-core.txt
+++ b/requirements-core.txt
@@ -1,2 +1,3 @@
 requests
 dateparser
+pandas>=1.4.0
diff --git a/setup.py b/setup.py
index 4a6c1ab..3a71d9e 100644
--- a/setup.py
+++ b/setup.py
@@ -37,10 +37,9 @@ def get_version():
     url="https://github.com/4n4nd/prometheus-api-client-python",
     install_requires=get_install_requires(),
     extras_require={
-        "dataframe": ["pandas>=1.4.0"],
         "numpy": ["numpy"],
         "plot": ["matplotlib"],
-        "all": ["pandas>=1.4.0", "numpy", "matplotlib"],
+        "all": ["numpy", "matplotlib"],
     },
     packages=setuptools.find_packages(),
     package_data={"prometheus-api-client": ["py.typed"]},

From c02129e84a8fe0bfed70d26c51075b675e3c808f Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 05:53:07 +0000
Subject: [PATCH 09/13] Fix numpy reload issue in TestLazyImports

- Refactored tests to use subprocess isolation instead of removing modules from sys.modules
- Prevents numpy from being reloaded which was causing test failures
- All 55 tests now pass with no warnings
- test_metric_import_loads_pandas no longer removes modules since it just checks loaded state

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 tests/test_lazy_imports.py | 117 ++++++++++++++++++++-----------------
 1 file changed, 62 insertions(+), 55 deletions(-)

diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
index 7bf9c2b..00bcf04 100644
--- a/tests/test_lazy_imports.py
+++ b/tests/test_lazy_imports.py
@@ -1,80 +1,87 @@
 """Test lazy imports to ensure pandas/matplotlib are not loaded unnecessarily."""
 import unittest
 import sys
+import subprocess
 import importlib
 
 
 class TestLazyImports(unittest.TestCase):
     """Test that PrometheusConnect can be imported without loading heavy dependencies."""
 
-    @staticmethod
-    def _remove_modules(module_names):
-        """Remove specified modules and their submodules from sys.modules.
-        
-        Args:
-            module_names: List of module names to remove
-        """
-        for module_name in module_names:
-            modules_to_remove = [
-                key for key in sys.modules.keys()
-                if key == module_name or key.startswith(module_name + '.')
-            ]
-            for module in modules_to_remove:
-                del sys.modules[module]
-    
-    @staticmethod
-    def _is_module_loaded(module_name):
-        """Check if a module is loaded in sys.modules.
-        
-        Args:
-            module_name: Name of the module to check
-            
-        Returns:
-            bool: True if module is loaded, False otherwise
-        """
-        return any(m == module_name or m.startswith(module_name + '.') for m in sys.modules.keys())
-
     def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
         """Test that importing PrometheusConnect doesn't load pandas, matplotlib, or numpy."""
-        # Remove any previously loaded modules
-        self._remove_modules(['prometheus_api_client', 'numpy', 'pandas', 'matplotlib'])
-        
-        # Import PrometheusConnect
-        from prometheus_api_client import PrometheusConnect
+        # Run in a subprocess to avoid affecting other tests
+        code = """
+import sys
+from prometheus_api_client import PrometheusConnect
+
+# Check that pandas, matplotlib, and numpy are not loaded
+pandas_loaded = any(m == 'pandas' or m.startswith('pandas.') for m in sys.modules.keys())
+matplotlib_loaded = any(m == 'matplotlib' or m.startswith('matplotlib.') for m in sys.modules.keys())
+numpy_loaded = any(m == 'numpy' or m.startswith('numpy.') for m in sys.modules.keys())
+
+if pandas_loaded:
+    sys.exit(1)
+if matplotlib_loaded:
+    sys.exit(2)
+if numpy_loaded:
+    sys.exit(3)
+sys.exit(0)
+"""
+        result = subprocess.run(
+            [sys.executable, '-c', code],
+            capture_output=True,
+            text=True
+        )
         
-        # Check that pandas, matplotlib, and numpy are not loaded
-        self.assertFalse(self._is_module_loaded('pandas'), 
-                        "pandas should not be loaded when importing PrometheusConnect")
-        self.assertFalse(self._is_module_loaded('matplotlib'), 
-                        "matplotlib should not be loaded when importing PrometheusConnect")
-        self.assertFalse(self._is_module_loaded('numpy'), 
-                        "numpy should not be loaded when importing PrometheusConnect")
+        if result.returncode == 1:
+            self.fail("pandas should not be loaded when importing PrometheusConnect")
+        elif result.returncode == 2:
+            self.fail("matplotlib should not be loaded when importing PrometheusConnect")
+        elif result.returncode == 3:
+            self.fail("numpy should not be loaded when importing PrometheusConnect")
+        elif result.returncode != 0:
+            self.fail(f"Subprocess failed with code {result.returncode}: {result.stderr}")
         
     def test_prometheus_connect_instantiation_without_numpy(self):
         """Test that PrometheusConnect can be instantiated without loading numpy."""
-        # Remove any previously loaded modules
-        self._remove_modules(['prometheus_api_client', 'numpy'])
-        
-        # Import and instantiate PrometheusConnect
-        from prometheus_api_client import PrometheusConnect
-        pc = PrometheusConnect(url='http://test.local:9090')
+        # Run in a subprocess to avoid affecting other tests
+        code = """
+import sys
+from prometheus_api_client import PrometheusConnect
+
+pc = PrometheusConnect(url='http://test.local:9090')
+
+# Check that numpy is still not loaded after instantiation
+numpy_loaded = any(m == 'numpy' or m.startswith('numpy.') for m in sys.modules.keys())
+
+if numpy_loaded:
+    sys.exit(1)
+if pc is None:
+    sys.exit(2)
+sys.exit(0)
+"""
+        result = subprocess.run(
+            [sys.executable, '-c', code],
+            capture_output=True,
+            text=True
+        )
         
-        # Check that numpy is still not loaded after instantiation
-        self.assertFalse(self._is_module_loaded('numpy'), 
-                        "numpy should not be loaded when instantiating PrometheusConnect")
-        self.assertIsNotNone(pc, "PrometheusConnect should be instantiated successfully")
+        if result.returncode == 1:
+            self.fail("numpy should not be loaded when instantiating PrometheusConnect")
+        elif result.returncode == 2:
+            self.fail("PrometheusConnect should be instantiated successfully")
+        elif result.returncode != 0:
+            self.fail(f"Subprocess failed with code {result.returncode}: {result.stderr}")
 
     def test_metric_import_loads_pandas(self):
         """Test that importing Metric does load pandas (expected behavior)."""
-        # Remove any previously loaded modules
-        self._remove_modules(['prometheus_api_client', 'pandas'])
-        
-        # Import Metric
+        # This test doesn't remove modules, so it won't cause reload issues
         from prometheus_api_client import Metric
         
         # Check that pandas is loaded (this is expected for Metric)
-        self.assertTrue(self._is_module_loaded('pandas'), 
-                       "pandas should be loaded when importing Metric")
+        pandas_loaded = any(m == 'pandas' or m.startswith('pandas.') for m in sys.modules.keys())
+        self.assertTrue(pandas_loaded, "pandas should be loaded when importing Metric")
 
 
 if __name__ == '__main__':

From 1c8d53b2e0aaa68f3b2a0b5db79a6f11583041c9 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 06:02:58 +0000
Subject: [PATCH 10/13] Remove unused importlib import from
 test_lazy_imports.py

- importlib was imported but never used in the test file
- All tests still pass after removal

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 tests/test_lazy_imports.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
index 00bcf04..33de601 100644
--- a/tests/test_lazy_imports.py
+++ b/tests/test_lazy_imports.py
@@ -2,7 +2,6 @@
 import unittest
 import sys
 import subprocess
-import importlib
 
 
 class TestLazyImports(unittest.TestCase):

From c2db4c46d666ea7beb00120f052dd64f785023b9 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 06:08:06 +0000
Subject: [PATCH 11/13] Refactor test_lazy_imports.py to reduce code
 duplication

- Added _run_in_subprocess helper method to eliminate repetition
- Helper accepts code and fail_map for flexible error handling
- Enhanced error reporting to include both stdout and stderr for better debugging
- All 55 tests still pass

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 tests/test_lazy_imports.py | 65 +++++++++++++++++++++++---------------
 1 file changed, 39 insertions(+), 26 deletions(-)

diff --git a/tests/test_lazy_imports.py b/tests/test_lazy_imports.py
index 33de601..bac80bf 100644
--- a/tests/test_lazy_imports.py
+++ b/tests/test_lazy_imports.py
@@ -7,6 +7,34 @@
 class TestLazyImports(unittest.TestCase):
     """Test that PrometheusConnect can be imported without loading heavy dependencies."""
 
+    def _run_in_subprocess(self, code, fail_map):
+        """Run code in a subprocess and check exit codes against fail_map.
+        
+        Args:
+            code: Python code to execute in subprocess
+            fail_map: Dictionary mapping exit codes to error messages
+            
+        Raises:
+            AssertionError: If subprocess exits with a code in fail_map or any non-zero code
+        """
+        result = subprocess.run(
+            [sys.executable, '-c', code],
+            capture_output=True,
+            text=True
+        )
+        
+        if result.returncode in fail_map:
+            self.fail(fail_map[result.returncode])
+        elif result.returncode != 0:
+            # Include both stdout and stderr for better debugging
+            output = []
+            if result.stdout:
+                output.append(f"stdout: {result.stdout}")
+            if result.stderr:
+                output.append(f"stderr: {result.stderr}")
+            output_str = "\n".join(output) if output else "no output"
+            self.fail(f"Subprocess failed with code {result.returncode}: {output_str}")
+
     def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
         """Test that importing PrometheusConnect doesn't load pandas, matplotlib, or numpy."""
         # Run in a subprocess to avoid affecting other tests
@@ -27,20 +55,12 @@ def test_prometheus_connect_import_without_pandas_matplotlib_numpy(self):
     sys.exit(3)
 sys.exit(0)
 """
-        result = subprocess.run(
-            [sys.executable, '-c', code],
-            capture_output=True,
-            text=True
-        )
-        
-        if result.returncode == 1:
-            self.fail("pandas should not be loaded when importing PrometheusConnect")
-        elif result.returncode == 2:
-            self.fail("matplotlib should not be loaded when importing PrometheusConnect")
-        elif result.returncode == 3:
-            self.fail("numpy should not be loaded when importing PrometheusConnect")
-        elif result.returncode != 0:
-            self.fail(f"Subprocess failed with code {result.returncode}: {result.stderr}")
+        fail_map = {
+            1: "pandas should not be loaded when importing PrometheusConnect",
+            2: "matplotlib should not be loaded when importing PrometheusConnect",
+            3: "numpy should not be loaded when importing PrometheusConnect",
+        }
+        self._run_in_subprocess(code, fail_map)
         
     def test_prometheus_connect_instantiation_without_numpy(self):
         """Test that PrometheusConnect can be instantiated without loading numpy."""
@@ -60,18 +80,11 @@ def test_prometheus_connect_instantiation_without_numpy(self):
     sys.exit(2)
 sys.exit(0)
 """
-        result = subprocess.run(
-            [sys.executable, '-c', code],
-            capture_output=True,
-            text=True
-        )
-        
-        if result.returncode == 1:
-            self.fail("numpy should not be loaded when instantiating PrometheusConnect")
-        elif result.returncode == 2:
-            self.fail("PrometheusConnect should be instantiated successfully")
-        elif result.returncode != 0:
-            self.fail(f"Subprocess failed with code {result.returncode}: {result.stderr}")
+        fail_map = {
+            1: "numpy should not be loaded when instantiating PrometheusConnect",
+            2: "PrometheusConnect should be instantiated successfully",
+        }
+        self._run_in_subprocess(code, fail_map)
 
     def test_metric_import_loads_pandas(self):
         """Test that importing Metric does load pandas (expected behavior)."""

From cefc56c76f7e0a7bc30497be72af30a9368f1aff Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Thu, 4 Dec 2025 06:14:13 +0000
Subject: [PATCH 12/13] Make pandas an optional dependency again

- Removed pandas from requirements-core.txt
- Added pandas>=1.4.0 to extras_require['dataframe'] and ['all']
- Updated README to reflect pandas, numpy, and matplotlib are all optional
- Users can now install minimal version without any heavy dependencies
- All 55 tests pass

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 README.md             | 7 ++++---
 requirements-core.txt | 1 -
 setup.py              | 3 ++-
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index da6c727..d7ea10b 100644
--- a/README.md
+++ b/README.md
@@ -11,14 +11,15 @@ To install the latest release:
 
 `pip install prometheus-api-client`
 
-To install with all optional dependencies (numpy, matplotlib):
+To install with all optional dependencies (pandas, numpy, matplotlib):
 
 `pip install prometheus-api-client[all]`
 
-**Note:** Starting from version 0.7.0, numpy and matplotlib are optional dependencies. Pandas is included as a core dependency.
-The lazy import mechanism ensures that `PrometheusConnect` can be imported without loading numpy until `get_metric_aggregation()` is called, which reduces initial memory footprint.
+**Note:** Starting from version 0.7.0, pandas, numpy, and matplotlib are optional dependencies. 
+If you only need `PrometheusConnect` without DataFrame support or plotting capabilities, you can install the minimal version which significantly reduces memory footprint and installation time, especially on Alpine-based Docker images.
 
 To install only specific extras:
+- For DataFrame support: `pip install prometheus-api-client[dataframe]`
 - For numpy support: `pip install prometheus-api-client[numpy]`
 - For plotting support: `pip install prometheus-api-client[plot]`
 
diff --git a/requirements-core.txt b/requirements-core.txt
index cc00aef..bbfd6bf 100644
--- a/requirements-core.txt
+++ b/requirements-core.txt
@@ -1,3 +1,2 @@
 requests
 dateparser
-pandas>=1.4.0
diff --git a/setup.py b/setup.py
index 3a71d9e..4a6c1ab 100644
--- a/setup.py
+++ b/setup.py
@@ -37,9 +37,10 @@ def get_version():
     url="https://github.com/4n4nd/prometheus-api-client-python",
     install_requires=get_install_requires(),
     extras_require={
+        "dataframe": ["pandas>=1.4.0"],
         "numpy": ["numpy"],
         "plot": ["matplotlib"],
-        "all": ["numpy", "matplotlib"],
+        "all": ["pandas>=1.4.0", "numpy", "matplotlib"],
     },
     packages=setuptools.find_packages(),
     package_data={"prometheus-api-client": ["py.typed"]},

From abc430e01701ca998edb5cad0b95f8090bc78dc8 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Fri, 5 Dec 2025 01:32:10 +0000
Subject: [PATCH 13/13] Add use-case oriented extras and helpful error messages

- Added 'analytics' extra for use-case oriented installation
- Added try/except blocks with helpful error messages for missing dependencies:
  - NumPy: suggests installing [analytics] or [all]
  - Pandas: suggests installing [dataframe] or [all]
- Updated README to highlight analytics extra instead of numpy
- Error messages guide users to install correct extras
- All 55 tests pass

Co-authored-by: 4n4nd <22333506+4n4nd@users.noreply.github.com>
---
 README.md                                   |  2 +-
 prometheus_api_client/metric.py             | 10 +++++++++-
 prometheus_api_client/metric_range_df.py    | 12 ++++++++++--
 prometheus_api_client/metric_snapshot_df.py | 12 ++++++++++--
 prometheus_api_client/prometheus_connect.py |  9 ++++++++-
 setup.py                                    |  1 +
 6 files changed, 39 insertions(+), 7 deletions(-)

diff --git a/README.md b/README.md
index d7ea10b..bce2baa 100644
--- a/README.md
+++ b/README.md
@@ -20,7 +20,7 @@ If you only need `PrometheusConnect` without DataFrame support or plotting capab
 
 To install only specific extras:
 - For DataFrame support: `pip install prometheus-api-client[dataframe]`
-- For numpy support: `pip install prometheus-api-client[numpy]`
+- For analytics/aggregation operations: `pip install prometheus-api-client[analytics]`
 - For plotting support: `pip install prometheus-api-client[plot]`
 
 To install directly from this branch:
diff --git a/prometheus_api_client/metric.py b/prometheus_api_client/metric.py
index e02832b..adc2d9a 100644
--- a/prometheus_api_client/metric.py
+++ b/prometheus_api_client/metric.py
@@ -1,7 +1,15 @@
 """A Class for metric object."""
 from copy import deepcopy
 import datetime
-import pandas
+
+try:
+    import pandas
+except ImportError as e:
+    raise ImportError(
+        "Pandas is required for Metric class. "
+        "Please install it with: pip install prometheus-api-client[dataframe] "
+        "or pip install prometheus-api-client[all]"
+    ) from e
 
 from prometheus_api_client.exceptions import MetricValueConversionError
 
diff --git a/prometheus_api_client/metric_range_df.py b/prometheus_api_client/metric_range_df.py
index 4b98af9..3ec836f 100644
--- a/prometheus_api_client/metric_range_df.py
+++ b/prometheus_api_client/metric_range_df.py
@@ -1,6 +1,14 @@
 """A pandas.DataFrame subclass for Prometheus range vector responses."""
-from pandas import DataFrame, to_datetime
-from pandas._typing import Axes, Dtype
+try:
+    from pandas import DataFrame, to_datetime
+    from pandas._typing import Axes, Dtype
+except ImportError as e:
+    raise ImportError(
+        "Pandas is required for MetricRangeDataFrame class. "
+        "Please install it with: pip install prometheus-api-client[dataframe] "
+        "or pip install prometheus-api-client[all]"
+    ) from e
+
 from typing import Optional, Sequence
 
 from prometheus_api_client.exceptions import MetricValueConversionError
diff --git a/prometheus_api_client/metric_snapshot_df.py b/prometheus_api_client/metric_snapshot_df.py
index 2f97a7a..980f02b 100644
--- a/prometheus_api_client/metric_snapshot_df.py
+++ b/prometheus_api_client/metric_snapshot_df.py
@@ -1,6 +1,14 @@
 """A pandas.DataFrame subclass for Prometheus query response."""
-from pandas import DataFrame, to_datetime
-from pandas._typing import Axes, Dtype
+try:
+    from pandas import DataFrame, to_datetime
+    from pandas._typing import Axes, Dtype
+except ImportError as e:
+    raise ImportError(
+        "Pandas is required for MetricSnapshotDataFrame class. "
+        "Please install it with: pip install prometheus-api-client[dataframe] "
+        "or pip install prometheus-api-client[all]"
+    ) from e
+
 from typing import Optional, Sequence
 
 from prometheus_api_client.exceptions import MetricValueConversionError
diff --git a/prometheus_api_client/prometheus_connect.py b/prometheus_api_client/prometheus_connect.py
index 0149930..6f74939 100644
--- a/prometheus_api_client/prometheus_connect.py
+++ b/prometheus_api_client/prometheus_connect.py
@@ -568,7 +568,14 @@ def get_metric_aggregation(
                 'max': 6.009373
              }
         """
-        import numpy
+        try:
+            import numpy
+        except ImportError as e:
+            raise ImportError(
+                "NumPy is required for metric aggregation operations. "
+                "Please install it with: pip install prometheus-api-client[analytics] "
+                "or pip install prometheus-api-client[all]"
+            ) from e
         
         if not isinstance(operations, list):
             raise TypeError("Operations can be only of type list")
diff --git a/setup.py b/setup.py
index 4a6c1ab..120d9ad 100644
--- a/setup.py
+++ b/setup.py
@@ -40,6 +40,7 @@ def get_version():
         "dataframe": ["pandas>=1.4.0"],
         "numpy": ["numpy"],
         "plot": ["matplotlib"],
+        "analytics": ["numpy"],
         "all": ["pandas>=1.4.0", "numpy", "matplotlib"],
     },
     packages=setuptools.find_packages(),