Added support for Python versions 3.7+

Author: madpah

.github/workflows/poetry.yml

@@ -25,7 +25,10 @@ jobs:
       fail-fast: false
       matrix:
         python-version:
-          - "3.9" # highest and lowest supported
+          - "3.9" # highest supported
+          - "3.8"
+          - "3.7"
+          - "3.6" # lowest supported
     timeout-minutes: 30
     steps:
       - name: Checkout

README.md

@@ -1,6 +1,14 @@
 # Python Library for generating CycloneDX
 
 [![CircleCI](https://circleci.com/gh/sonatype-nexus-community/cyclonedx-python-lib.svg?style=shield)](https://circleci.com/gh/sonatype-nexus-community/cyclonedx-python-lib)
+![GitHub Workflow Status](https://img.shields.io/github/workflow/status/sonatype-nexus-community/cyclonedx-python-lib/Python%20CI)
+![Python Version Support](https://img.shields.io/badge/python-3.7%20%7C%203.8%20%7C%203.9-blue)
+[![GitHub license](https://img.shields.io/github/license/sonatype-nexus-community/cyclonedx-python-lib)](https://github.com/sonatype-nexus-community/cyclonedx-python-lib/blob/main/LICENSE)
+[![GitHub issues](https://img.shields.io/github/issues/sonatype-nexus-community/cyclonedx-python-lib)](https://github.com/sonatype-nexus-community/cyclonedx-python-lib/issues)
+[![GitHub forks](https://img.shields.io/github/forks/sonatype-nexus-community/cyclonedx-python-lib)](https://github.com/sonatype-nexus-community/cyclonedx-python-lib/network)
+[![GitHub stars](https://img.shields.io/github/stars/sonatype-nexus-community/cyclonedx-python-lib)](https://github.com/sonatype-nexus-community/cyclonedx-python-lib/stargazers)
+
+----
 
 This CycloneDX module for Python can generate valid CycloneDX bill-of-material document containing an aggregate of all
 project dependencies.
@@ -159,6 +167,11 @@ _Note: We refer throughout using XPath, but the same is true for both XML and JS
 1. N/A is where the CycloneDX standard does not include this
 2. If the table above does not refer to an element, it is not currently supported
 
+## Python Support
+
+We endeavour to support all functionality for all [current actively supported Python versions](https://www.python.org/downloads/).
+However, some features may not be possible/present in older Python versions due to their lack of support.
+
 ## The Fine Print
 
 Remember:

cyclonedx/parser/environment.py

@@ -1,3 +1,10 @@
+import sys
+
+if sys.version_info >= (3, 8, 0):
+    from importlib.metadata import metadata
+else:
+    from importlib_metadata import metadata
+
 from . import BaseParser
 
 from ..model.cyclonedx import Component
@@ -12,14 +19,20 @@ class EnvironmentParser(BaseParser):
 
     def __init__(self):
         import pkg_resources
-        from importlib.metadata import metadata
 
         i: pkg_resources.DistInfoDistribution
         for i in iter(pkg_resources.working_set):
             c = Component(name=i.project_name, version=i.version)
-            i_metadata = metadata(i.project_name)
 
+            i_metadata = self._get_metadata_for_package(i.project_name)
             if 'Author' in i_metadata.keys():
                 c.set_author(i_metadata.get('Author'))
 
             self._components.append(c)
+
+    @staticmethod
+    def _get_metadata_for_package(package_name: str):
+        if sys.version_info >= (3, 8, 0):
+            return metadata(package_name)
+        else:
+            return metadata(package_name)

poetry.lock

@@ -6,10 +6,11 @@ authors = ["Paul Horton <[email protected]>"]
 license = "Apache-2.0"
 
 [tool.poetry.dependencies]
-python = "^3.9"
+python = "^3.7"
 packageurl-python = "^0.9.4"
 requirements_parser = "^0.2.0"
 setuptools = "^50.3.2"
+importlib-metadata = "^4.8.1"
 
 [tool.poetry.dev-dependencies]
 tox = "^3.24.3"

pyproject.toml

@@ -29,7 +29,7 @@
         'Programming Language :: Python :: 3'
     ],
     packages=find_packages(),
-    python_requires='>=3.9',
+    python_requires='>=3.7',
     package_data={
         'cyclonedx': ['schema/*.json', 'schema/*.xsd', 'schema/ext/*.json', 'schema/ext/*.xsd']
     },

setup.py

@@ -1,6 +1,6 @@
 [tox]
 minversion=3.9.0
-envlist = flake8,py39
+envlist = flake8,py39,py38,py37
 
 [testenv]
 deps =