diff --git a/cve_bin_tool/checkers/python.py b/cve_bin_tool/checkers/python.py
index f7ae562b79..f29c046cdb 100644
--- a/cve_bin_tool/checkers/python.py
+++ b/cve_bin_tool/checkers/python.py
@@ -16,6 +16,9 @@ class PythonChecker(Checker):
         r"Fatal Python error: unable to decode the command line argument",
         r"Internal error in the Python interpreter",
         r"CPython",
+        r"Python package: ",
+        r"dist-info",
+        r"egg-info",
     ]
     FILENAME_PATTERNS = [r"python"]
     VERSION_PATTERNS = [
@@ -25,5 +28,7 @@ class PythonChecker(Checker):
         r"([23]+\.[0-9]+\.[0-9]+)\r?\nPython %s",
         r"([23]+\.[0-9]+\.[0-9]+)\r?\n%\.80s \(%\.80s\) %\.80s",
         r"tags/v([23]+\.[0-9]+\.[0-9]+)\r?\n",
+        r"Python\s+([23]+\.[0-9]+\.[0-9]+)",
+        r"__version__\s*=\s*['\"]((?:[23]+\.[0-9]+\.[0-9]+))['\"]",
     ]
     VENDOR_PRODUCT = [("python_software_foundation", "python"), ("python", "python")]
diff --git a/cve_bin_tool/dependency_graph.py b/cve_bin_tool/dependency_graph.py
new file mode 100644
index 0000000000..e8674d78fe
--- /dev/null
+++ b/cve_bin_tool/dependency_graph.py
@@ -0,0 +1,54 @@
+class DependencyGraph:
+    def __init__(self):
+        self.graph = {}  # {package_name: [dependency_names]}
+
+    def add_package(self, package, dependencies):
+        # Add or update the package dependencies in the graph
+        self.graph[package.lower()] = [dep.lower() for dep in dependencies]
+
+    def resolve_dependencies(self, root_package):
+        """
+        Returns an ordered list of packages including indirect dependencies.
+        Uses iterative depth-first search (without recursion) and cycle detection.
+        """
+        visited = set()
+        ordered = []
+        root = root_package.lower()
+        stack = [(root, False)]  # (node, processed_flag)
+        in_stack = {root}  # track nodes in the current stack
+
+        while stack:
+            current, processed = stack[-1]
+
+            if processed:
+                stack.pop()
+                in_stack.remove(current)
+                if current not in visited:
+                    visited.add(current)
+                    ordered.append(current)
+                continue
+
+            stack[-1] = (current, True)  # mark current as processed
+
+            # Add unvisited dependencies not already in the stack to avoid cycles
+            if current in self.graph:
+                for dep in reversed(self.graph[current]):
+                    if dep not in visited and dep not in in_stack:
+                        stack.append((dep, False))
+                        in_stack.add(dep)
+        return ordered
+
+
+# Example usage:
+if __name__ == "__main__":
+    # Build a sample dependency graph for testing
+    dg = DependencyGraph()
+    dg.add_package("packageA", ["packageB", "packageC"])
+    dg.add_package("packageB", ["packageD"])
+    dg.add_package("packageC", ["packageD", "packageE"])
+    dg.add_package("packageD", [])
+    dg.add_package("packageE", [])
+
+    # Resolve dependencies for packageA
+    dependencies = dg.resolve_dependencies("packageA")
+    print("Resolved order:", dependencies)
diff --git a/cve_bin_tool/parsers/python.py b/cve_bin_tool/parsers/python.py
index 827d717224..23fb428af8 100644
--- a/cve_bin_tool/parsers/python.py
+++ b/cve_bin_tool/parsers/python.py
@@ -1,11 +1,13 @@
 # Copyright (C) 2024 Intel Corporation
 # SPDX-License-Identifier: GPL-3.0-or-later
 
+import importlib.metadata as importlib_metadata
 import json
 import re
 import subprocess
 from re import MULTILINE, compile, search
 
+from packaging.requirements import Requirement
 from packaging.version import parse as parse_version
 
 from cve_bin_tool.parsers import Parser
@@ -140,24 +142,86 @@ def generate_purl(self, product, vendor="", qualifier={}, subpath=None):
 
         return purl
 
+    def _get_installed_packages(self):
+        """Get a list of all installed packages using importlib.metadata."""
+        try:
+            return {
+                dist.metadata["Name"]: dist  # Keep original case
+                for dist in importlib_metadata.distributions()
+            }
+        except Exception as e:
+            self.logger.debug(f"Error getting installed packages: {e}")
+            return {}
+
+    def _parse_dependencies(self, dist):
+        """Parse package dependencies considering environment markers."""
+        requires = dist.requires or []
+        dependencies = []
+
+        for req_str in requires:
+            try:
+                req = Requirement(req_str)
+                if req.marker is None or req.marker.evaluate():
+                    dependencies.append(req.name)  # Keep original case
+            except Exception as e:
+                self.logger.debug(f"Error parsing requirement {req_str}: {e}")
+
+        return dependencies
+
     def run_checker(self, filename):
         """
-        This generator runs only for python packages.
-        There are no actual checkers.
-        The ProductInfo is computed without the help of any checkers from PKG-INFO or METADATA.
+        Enhanced checker that uses importlib.metadata for better dependency resolution.
         """
         self.filename = filename
         lines = parse_strings(self.filename)
         lines = "\n".join(lines.splitlines()[:3])
+
         try:
             product = search(compile(r"^Name: (.+)$", MULTILINE), lines).group(1)
             version = search(compile(r"^Version: (.+)$", MULTILINE), lines).group(1)
-            purl = self.generate_purl(product)
-            vendor = self.get_vendor(purl, product, version)
-            if vendor is not None:
-                yield from vendor
+            # Remove lowercasing to preserve original case
+            normalized_product = product.replace("-", "_")
+
+            # Get all installed packages and their dependencies
+            installed_packages = self._get_installed_packages()
+            # Use case-insensitive lookup
+            product_key = next(
+                (
+                    name
+                    for name in installed_packages.keys()
+                    if name.lower() == normalized_product.lower()
+                ),
+                None,
+            )
+
+            if product_key:
+                dist = installed_packages[product_key]
+                dependencies = self._parse_dependencies(dist)
+
+                # Process the main package
+                purl = self.generate_purl(product)  # Original name for PURL
+                vendor = self.get_vendor(purl, product, version)
+                if vendor is not None:
+                    yield from vendor
+
+                # Process dependencies with case-preservation
+                for dep_name in dependencies:
+                    dep_key = next(
+                        (
+                            name
+                            for name in installed_packages.keys()
+                            if name.lower() == dep_name.lower()
+                        ),
+                        None,
+                    )
+                    if dep_key:
+                        dep_dist = installed_packages[dep_key]
+                        dep_purl = self.generate_purl(dep_name)
+                        dep_version = dep_dist.version
+                        dep_vendor = self.get_vendor(dep_purl, dep_name, dep_version)
+                        if dep_vendor is not None:
+                            yield from dep_vendor
 
-        # There are packages with a METADATA file in them containing different data from what the tool expects
         except AttributeError:
             self.logger.debug(f"{filename} is an invalid METADATA/PKG-INFO")
         self.logger.debug(f"Done scanning file: {filename}")
diff --git a/cve_bin_tool/util.py b/cve_bin_tool/util.py
index 11ee0533f4..1811ed9096 100644
--- a/cve_bin_tool/util.py
+++ b/cve_bin_tool/util.py
@@ -7,6 +7,7 @@
 
 import fnmatch
 import os
+import platform
 import re
 import sys
 from enum import Enum
@@ -608,6 +609,20 @@ def windows_fixup(filename):
     return filename.replace(":", "_").replace("\\", "_")
 
 
+def get_environment_context():
+    """
+    Returns a dictionary with environment details for marker evaluation.
+    """
+    return {
+        "python_version": f"{sys.version_info.major}.{sys.version_info.minor}",
+        "sys_platform": sys.platform,
+        "os_name": os.name,
+        "platform_machine": platform.machine(),
+        "platform_system": platform.system(),
+        "platform_release": platform.release(),
+    }
+  
+  
 def strip_path(path_element: str, scanned_dir: str) -> str:
     path = Path(path_element)
     return path.drive + path.root + os.path.relpath(path_element, scanned_dir)
diff --git a/requirements.txt b/requirements.txt
index e6d8e62c47..899e214076 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@ defusedxml
 distro
 filetype>=1.2.0
 gsutil
-importlib_metadata>=3.6; python_version < "3.10"
+importlib_metadata>=4.0; python_version < "3.10"
 importlib_resources; python_version < "3.9"
 jinja2>=2.11.3
 jsonschema>=3.0.2
diff --git a/test/test_dependency_graph.py b/test/test_dependency_graph.py
new file mode 100644
index 0000000000..70f79d8881
--- /dev/null
+++ b/test/test_dependency_graph.py
@@ -0,0 +1,69 @@
+# Copyright (C) 2022 Intel Corporation
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from cve_bin_tool.dependency_graph import DependencyGraph
+
+
+def test_dependency_order():
+    """Test that dependencies are resolved in correct order"""
+    dg = DependencyGraph()
+    dg.add_package("A", ["B", "C"])
+    dg.add_package("B", ["D"])
+    dg.add_package("C", ["D", "E"])
+    dg.add_package("D", [])
+    dg.add_package("E", [])
+
+    order = dg.resolve_dependencies("A")
+
+    # Verify dependencies come before their dependents
+    a_index = order.index("a")
+    b_index = order.index("b")
+    c_index = order.index("c")
+    d_index = order.index("d")
+    e_index = order.index("e")
+
+    # D should come before B and C (its dependents)
+    assert d_index < b_index
+    assert d_index < c_index
+
+    # E should come before C (its dependent)
+    assert e_index < c_index
+
+    # B and C should come before A (their dependent)
+    assert b_index < a_index
+    assert c_index < a_index
+
+
+def test_cycle_handling():
+    """Test that circular dependencies don't cause infinite loops"""
+    dg = DependencyGraph()
+    dg.add_package("A", ["B"])
+    dg.add_package("B", ["C"])
+    dg.add_package("C", ["A"])  # Create cycle A -> B -> C -> A
+
+    order = dg.resolve_dependencies("A")
+
+    # All packages should be present exactly once
+    assert len(order) == 3
+    assert len(set(order)) == 3
+    for pkg in ["a", "b", "c"]:
+        assert pkg in order
+
+
+def test_deep_dependency_chain():
+    """Test handling of deep dependency chains"""
+    dg = DependencyGraph()
+    # Create a chain A -> B -> C -> D -> E -> F
+    dg.add_package("A", ["B"])
+    dg.add_package("B", ["C"])
+    dg.add_package("C", ["D"])
+    dg.add_package("D", ["E"])
+    dg.add_package("E", ["F"])
+    dg.add_package("F", [])
+
+    order = dg.resolve_dependencies("A")
+
+    # Verify F comes first (no dependencies)
+    assert order[0] == "f"
+    # Verify A comes last (depends on everything)
+    assert order[-1] == "a"
diff --git a/test/test_dependency_parser.py b/test/test_dependency_parser.py
new file mode 100644
index 0000000000..896c4b14ea
--- /dev/null
+++ b/test/test_dependency_parser.py
@@ -0,0 +1,34 @@
+# Copyright (C) 2022 Intel Corporation
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import pytest
+from packaging.requirements import Requirement
+
+
+# Dummy implementation of parse_dependencies copied from your parser
+def parse_dependencies(metadata):
+    dependencies = []
+    for req in metadata.get("Requires-Dist", []):
+        requirement = Requirement(req)
+        if requirement.marker and not requirement.marker.evaluate():
+            continue
+        dependencies.append(requirement.name.lower())
+    return dependencies
+
+
+@pytest.fixture
+def metadata_with_markers():
+    return {
+        "Requires-Dist": [
+            "packageA; python_version >= '3.0'",  # Should be included (assuming current python is >=3.0)
+            "packageB; python_version < '2.0'",  # Should be excluded
+            "packageC",  # Always included
+        ]
+    }
+
+
+def test_parse_dependencies(metadata_with_markers):
+    deps = parse_dependencies(metadata_with_markers)
+    assert "packagea" in deps
+    assert "packagec" in deps
+    assert "packageb" not in deps
diff --git a/test/test_python_parser.py b/test/test_python_parser.py
new file mode 100644
index 0000000000..953ba48b3e
--- /dev/null
+++ b/test/test_python_parser.py
@@ -0,0 +1,65 @@
+import importlib
+
+import pytest
+
+# Assume our parser is imported as follows:
+from cve_bin_tool.parsers.python import PythonParser
+
+
+class DummyLogger:
+    def debug(self, msg):
+        pass
+
+    def error(self, msg):
+        pass
+
+
+class DummyDB:
+    pass
+
+
+@pytest.fixture
+def parser():
+    return PythonParser(DummyDB(), DummyLogger())
+
+
+def test_get_installed_packages(parser, monkeypatch):
+    # Create a dummy distribution object
+    class DummyDist:
+        def __init__(self, name, version, requires=None):
+            self.metadata = {"Name": name, "Version": version}
+            self.requires = requires or []
+
+    dummy_dists = [
+        DummyDist("packageA", "1.0"),
+        DummyDist("packageB", "2.0", requires=["packageC; python_version >= '3.6'"]),
+        DummyDist("packageC", "3.0"),
+    ]
+    # Patch distributions on importlib.metadata directly.
+    monkeypatch.setattr(importlib.metadata, "distributions", lambda: dummy_dists)
+    packages = parser._get_installed_packages()
+    assert "packageA" in packages
+    assert "packageB" in packages
+    assert "packageC" in packages
+
+
+def test_parse_dependencies(parser):
+    # Dummy distribution with requires field
+    class DummyDist:
+        def __init__(self, requires):
+            self.requires = requires
+
+    # Requirement without marker
+    dist1 = DummyDist(requires=["packageD>=1.0"])
+    deps1 = parser._parse_dependencies(dist1)
+    assert "packageD" in deps1
+
+    # Requirement with marker that evaluates to True (simulate current version)
+    dist2 = DummyDist(requires=["packageE; python_version >= '3.0'"])
+    deps2 = parser._parse_dependencies(dist2)
+    assert "packageE" in deps2
+
+    # Requirement with marker that evaluates to False (simulate unmet condition)
+    dist3 = DummyDist(requires=["packageF; python_version < '2.0'"])
+    deps3 = parser._parse_dependencies(dist3)
+    assert "packageF" not in deps3
diff --git a/test/test_util.py b/test/test_util.py
index ed191ca4a0..708e0bf22a 100644
--- a/test/test_util.py
+++ b/test/test_util.py
@@ -8,7 +8,13 @@
 from typing import DefaultDict
 
 from cve_bin_tool.cve_scanner import CVEScanner
-from cve_bin_tool.util import CVEData, ProductInfo, inpath
+from cve_bin_tool.util import (
+    CVEData,
+    ProductInfo,
+    find_product_location,
+    get_environment_context,
+    inpath,
+)
 
 
 class TestUtil:
@@ -22,6 +28,53 @@ def test_inpath(self):
     def test_not_inpath(self):
         assert not inpath("cve_bin_tool_test_for_not_in_path")
 
+    @pytest.mark.parametrize(
+        "mock_sys_path, known_dirs",
+        [
+            (
+                ["/usr/local/bin", "/usr/local/lib/python3.10/site-packages"],
+                [
+                    "/usr/local/lib/python3.10/site-packages",
+                    "/usr/local/share",
+                    "/usr/share",
+                    "/usr/local/include",
+                    "/usr/include",
+                ],
+            ),
+        ],
+    )
+    def test_find_product_location(self, monkeypatch, mock_sys_path, known_dirs):
+        product_name = "lib4sbom"
+        monkeypatch.setattr(sys, "path", mock_sys_path)
+
+        def mock_exists(path):
+            for dir in known_dirs:
+                if dir in str(path):
+                    return True
+            return False
+
+        monkeypatch.setattr("pathlib.Path.exists", mock_exists)
+
+        expected_path = None
+        for dir in known_dirs:
+            product_location = Path(dir) / product_name
+            if product_location.exists():
+                expected_path = str(product_location)
+                break
+
+        assert find_product_location(product_name) == expected_path
+
+    def test_get_environment_context(self):
+        context = get_environment_context()
+        for key in [
+            "python_version",
+            "sys_platform",
+            "os_name",
+            "platform_machine",
+            "platform_system",
+            "platform_release",
+        ]:
+            assert key in context, f"{key} not found in environment context"
 
 class TestSignature:
     """Tests signature of critical class and functions"""