Expand buildpack detection known file list

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Buildpack detection now recognises more Python-related file and directory names. ([#312](https://github.com/heroku/buildpacks-python/pull/312))
+
 ## [0.21.0] - 2024-12-18
 
 ### Changed

src/detect.rs

@@ -7,8 +7,9 @@ use std::path::Path;
 /// This list is deliberately larger than just the list of supported package manager files,
 /// so that Python projects that are missing some of the required files still pass detection,
 /// allowing us to show a helpful error message during the build phase.
-const KNOWN_PYTHON_PROJECT_FILES: [&str; 14] = [
+const KNOWN_PYTHON_PROJECT_FILES: [&str; 23] = [
     ".python-version",
+    "__init__.py",
     "app.py",
     "main.py",
     "manage.py",
@@ -19,9 +20,22 @@ const KNOWN_PYTHON_PROJECT_FILES: [&str; 14] = [
     "pyproject.toml",
     "requirements.txt",
     "runtime.txt",
+    "server.py",
     "setup.cfg",
     "setup.py",
     "uv.lock",
+    // Commonly seen misspellings of requirements.txt. (Which occur since pip doesn't
+    // create/manage requirements files itself, so the filenames are manually typed.)
+    "requirement.txt",
+    "Requirements.txt",
+    "requirements.text",
+    "requirements.txt.txt",
+    "requirments.txt",
+    // Whilst virtual environments shouldn't be committed to Git (and so shouldn't
+    // normally be present during the build), they are often present for beginner
+    // Python apps that are missing all of the other Python related files above.
+    ".venv/",
+    "venv/",
 ];
 
 /// Returns whether the specified project directory is that of a Python project, and so