Organized setup instructions (#115)

* Organized setup instructions

* update tets

* link checker action

* raise error upon broken link

* fix links

* fix links

* delete duplicated paragraph

setup/02_installing-python-libraries/python_environment_check.py

@@ -0,0 +1,77 @@
+# Copyright (c) Sebastian Raschka under Apache License 2.0 (see LICENSE.txt).
+# Source for "Build a Large Language Model From Scratch"
+#   - https://www.manning.com/books/build-a-large-language-model-from-scratch
+# Code: https://github.com/rasbt/LLMs-from-scratch
+
+from importlib.metadata import PackageNotFoundError, import_module
+import importlib.metadata
+from os.path import dirname, join, realpath
+from packaging.version import parse as version_parse
+import platform
+import sys
+
+if version_parse(platform.python_version()) < version_parse('3.9'):
+    print('[FAIL] We recommend Python 3.9 or newer but'
+          ' found version %s' % (sys.version))
+else:
+    print('[OK] Your Python version is %s' % (platform.python_version()))
+
+
+def get_packages(pkgs):
+    versions = []
+    for p in pkgs:
+        try:
+            imported = import_module(p)
+            try:
+                version = (getattr(imported, '__version__', None) or
+                           getattr(imported, 'version', None) or
+                           getattr(imported, 'version_info', None))
+                if version is None:
+                    # If common attributes don't exist, use importlib.metadata
+                    version = importlib.metadata.version(p)
+                versions.append(version)
+            except PackageNotFoundError:
+                # Handle case where package is not installed
+                versions.append('0.0')
+        except ImportError:
+            # Fallback if importlib.import_module fails for unexpected reasons
+            versions.append('0.0')
+    return versions
+
+
+def get_requirements_dict():
+    PROJECT_ROOT = dirname(realpath(__file__))
+    PROJECT_ROOT_UP_TWO = dirname(dirname(PROJECT_ROOT))
+    REQUIREMENTS_FILE = join(PROJECT_ROOT_UP_TWO, "requirements.txt")
+    d = {}
+    with open(REQUIREMENTS_FILE) as f:
+        for line in f:
+            if not line.strip():
+                continue
+            line = line.split("#")[0].strip()
+            line = line.split(" ")
+            line = [l.strip() for l in line]
+            d[line[0]] = line[-1]
+    return d
+
+
+def check_packages(d):
+    versions = get_packages(d.keys())
+
+    for (pkg_name, suggested_ver), actual_ver in zip(d.items(), versions):
+        if actual_ver == 'N/A':
+            continue
+        actual_ver, suggested_ver = version_parse(actual_ver), version_parse(suggested_ver)
+        if actual_ver < suggested_ver:
+            print(f'[FAIL] {pkg_name} {actual_ver}, please upgrade to >= {suggested_ver}')
+        else:
+            print(f'[OK] {pkg_name} {actual_ver}')
+
+
+def main():
+    d = get_requirements_dict()
+    check_packages(d)
+
+
+if __name__ == '__main__':
+    main()