Support multiple data format for Python sdist distributive (#419)

* Support multiple data format for Python sdist distributive

Accordingly to https://docs.python.org/3/distutils/sourcedist.html
Python sdist can use multiple formats such as:
* zip   zip file (.zip)
* gztar gzip’ed tar file (.tar.gz)
* bztar bzip2’ed tar file (.tar.bz2)
* xztar xz’ed tar file (.tar.xz)
* ztar  compressed tar file (.tar.Z)
* tar   tar file (.tar)

* Fix codestyle

poetry/repositories/legacy_repository.py

@@ -47,6 +47,15 @@ from .pypi_repository import PyPiRepository
 class Page:
 
     VERSION_REGEX = re.compile("(?i)([a-z0-9_\-.]+?)-(?=\d)([a-z0-9_.!+-]+)")
+    SUPPORTED_FORMATS = [
+        ".tar.gz",
+        ".whl",
+        ".zip",
+        ".tar.bz2",
+        ".tar.xz",
+        ".tar.Z",
+        ".tar",
+    ]
 
     def __init__(self, url, content, headers):
         if not url.endswith("/"):
@@ -96,7 +105,7 @@ class Page:
 
                 link = Link(url, self, requires_python=pyrequire)
 
-                if link.ext not in [".tar.gz", ".whl", ".zip"]:
+                if link.ext not in self.SUPPORTED_FORMATS:
                     continue
 
                 yield link
@@ -306,7 +315,10 @@ class LegacyRepository(PyPiRepository):
                 urls["bdist_wheel"] = link.url
             elif link.filename.endswith(".tar.gz"):
                 urls["sdist"] = link.url
-            elif link.filename.endswith((".zip", ".bz2")) and "sdist" not in urls:
+            elif (
+                link.filename.endswith((".zip", ".bz2", ".xz", ".Z", ".tar"))
+                and "sdist" not in urls
+            ):
                 urls["sdist"] = link.url
 
             hash = link.hash

tests/repositories/fixtures/legacy/relative.html

@@ -7,6 +7,7 @@
     <h1>Links for poetry</h1>
     <a href="poetry-0.1.0-py3-none-any.whl#sha256=1d85132efab8ead3c6f69202843da40a03823992091c29f8d65a31af68940163" data-requires-python="&gt;=3.6.0">poetry-0.1.0-py3-none-any.whl</a><br/>
     <a href="poetry-0.1.0.tar.gz#sha256=db33179244321b0b86c6c3645225ff2062ed3495ca16d0d64b3a5df804a82273" data-requires-python="&gt;=3.6.0">poetry-0.1.0.tar.gz</a><br/>
+    <a href="poetry-0.1.1.tar.bz2#sha256=db33179244321b0b86c6c3645225ff2062ed3495ca16d0d64b3a5df804a82273" data-requires-python="&gt;=3.6.0">poetry-0.1.1.tar.bz</a><br/>
     </body>
 </html>
 <!--SERIAL 3907384-->

tests/repositories/test_legacy_repository.py

@@ -50,3 +50,11 @@ def test_http_basic_auth_repo(mocker):
 
     mock.assert_called_once_with("legacy")
     assert repo._session.auth == ("user1", "p4ss")
+
+
+def test_sdist_format_support():
+    repo = MockRepository()
+    page = repo._get("/relative")
+    bz2_links = list(filter(lambda link: link.ext == ".tar.bz2", page.links))
+    assert len(bz2_links) == 1
+    assert bz2_links[0].filename == "poetry-0.1.1.tar.bz2"