Update README.md

README.md

@@ -3,6 +3,7 @@
 A modern Python package manager with PEP 582 support. [中文版本说明](README_zh.md)
 
 ![Github Actions](https://github.com/pdm-project/pdm/workflows/Tests/badge.svg)
+![PyPI](https://img.shields.io/pypi/v/pdm?logo=python&logoColor=%23cccccc)
 
 ## What is PDM?
 
@@ -58,7 +59,7 @@ $ pip install --user pdm
 PEP 582 is a draft proposal which still needs a lot of polishment, for instance, it doesn't mention how to manage
 CLI executables. PDM take the decision to put `bin`, `include` together with `lib` under `__pypackage__/X.Y`.
 
-### 2. How to run CLI scripts in the local package directory?
+### 2. How do I run CLI scripts in the local package directory?
 
 The recommended way is to prefix your command with `pdm run`. It is also possible to run CLI scripts directly from
 the outside, the PDM's installer has already injected the package path to the `sys.path` in the entry script file.
@@ -73,6 +74,9 @@ and could lead to some confusion around which packages are being used, though.
 You'd better not. The packages installed inside `__pypackages__` are OS dependent. Instead, you should keep `pdm.lock`
 in VCS and do `pdm sync` on the target environment to deploy.
 
+### 5. Can I use `pdm` to manage a Python 2.7 project?
+Sure. The `pdm` itself can be installed under Python 3.7+ only, but it doesn't restrict the Python used by the project.
+
 ## Credits
 
 This project is strongly inspired by [pyflow] and [poetry].

README_zh.md

@@ -67,6 +67,9 @@ PDM 会首先在 `__pypackage__` 中寻找，然后会在选择的 Python 解释
 最好别这样搞，`__pypackage__` 下面安装的包是和操作系统相关的，所以除非是纯 Python 的包，都会有兼容性的问题。你应该把 `pdm.lock`
 纳入版本管理，然后在目标环境中执行 `pdm sync`。
 
+### 5. 我能用`pdm`管理一个 Python 2.7 的项目吗？
+当然可以。只是`pdm`本身的安装需要 Python 版本高于 3.7，它并不限制项目使用的 Python 版本。
+
 ## 鸣谢
 
 本项目的受到 [pyflow] 与 [poetry] 的很多启发。

pdm/models/repositories.py

@@ -14,7 +14,7 @@ from pdm.models.requirements import (
     parse_requirement,
 )
 from pdm.models.specifiers import PySpecSet, SpecifierSet
-from pdm.utils import allow_all_wheels, get_pypi_source
+from pdm.utils import allow_all_wheels
 
 if TYPE_CHECKING:
     from pdm.models.environment import Environment
@@ -40,7 +40,7 @@ class BaseRepository:
         :param sources: a list of sources to download packages from.
         :param environment: the bound environment instance.
         """
-        self.sources = [get_pypi_source()] + sources
+        self.sources = sources
         self.environment = environment
         self._candidate_info_cache = context.make_candidate_info_cache()
         self._hash_cache = context.make_hash_cache()

pdm/project/core.py

@@ -19,7 +19,7 @@ from pdm.models.requirements import Requirement, parse_requirement, strip_extras
 from pdm.models.specifiers import PySpecSet
 from pdm.project.config import Config
 from pdm.project.meta import PackageMeta
-from pdm.utils import find_project_root
+from pdm.utils import find_project_root, get_pypi_source
 
 if TYPE_CHECKING:
     from tomlkit.container import Container
@@ -137,8 +137,11 @@ class Project:
         return self.tool_settings.get("allow_prereleases")
 
     @property
-    def sources(self) -> Optional[List[Source]]:
-        return self.tool_settings.get("source")
+    def sources(self) -> List[Source]:
+        sources = self.tool_settings.get("source", [])
+        if not any(source.get("name") == "pypi" for source in sources):
+            sources.insert(0, get_pypi_source())
+        return sources
 
     def get_repository(self) -> BaseRepository:
         sources = self.sources or []

pyproject.toml

@@ -13,8 +13,12 @@ repository = "https://github.com/pdm-project/pdm"
 keywords = ["packaging", "dependency", "workflow"]
 
 classifiers = [
+    "Development Status :: 3 - Alpha",
     "Topic :: Software Development :: Build Tools",
-    "Topic :: Software Development :: Libraries :: Python Modules"
+    "Programming Language :: Python",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.7",
+    "Programming Language :: Python :: 3.8"
 ]