requires.txt is not mandatory for metadata generator

pipdeps/metadata.py

+import json
+import os
+import tarfile
+import tempfile
+import urllib2
+import zipfile
+import wheel.metadata
+
+def get_json(url):
+    """
+    Return url json
+    """
+    return json.load(urllib2.urlopen(urllib2.Request(url)))
+
+def file_download(url):
+    """
+    Download file from url as temporary file
+    It returns file object
+    """
+    tmp_file = tempfile.NamedTemporaryFile(delete=False)
+    rfile = urllib2.urlopen(url)
+    with tmp_file as output:
+        output.write(rfile.read())
+    return tmp_file
+
+def write_metadata(tmp_file):
+    """
+    Write package metadata
+    """
+    try:
+        tar_file = tarfile.open(tmp_file.name, 'r')
+        for member in tar_file.getmembers():
+            if 'requires.txt' in member.name:
+                with open('/tmp/requires.txt', 'w') as tmpf:
+                    tmpf.write(tar_file.extractfile(member).read())
+            if 'PKG-INFO' in member.name:
+                with open('/tmp/PKG-INFO', 'w') as tmpf:
+                    tmpf.write(tar_file.extractfile(member).read())
+    except tarfile.ReadError:
+        zip_file = zipfile.ZipFile(tmp_file.name, 'r')
+        for member in zip_file.namelist():
+            if 'requires.txt' in member:
+                with open('/tmp/requires.txt', 'w') as tmpf:
+                    tmpf.write(zip_file.read(member))
+            if 'PKG-INFO' in member:
+                with open('/tmp/PKG-INFO', 'w') as tmpf:
+                    tmpf.write(zip_file.read(member))
+
+def get_metadata(package, version):
+    """
+    Return package metadata
+    """
+    metadata = None
+    for item in get_json("https://pypi.python.org/pypi/%s/%s/json" % (package, version,)) \
+        ['releases'][version]:
+        if item['packagetype'] == 'sdist':
+            tmp_file = file_download(item['url'])
+            write_metadata(tmp_file)
+            if os.path.isfile('/tmp/PKG-INFO'):
+                metadata = [
+                    line.decode('utf-8') \
+                    for line in wheel.metadata.pkginfo_to_metadata('/tmp', '/tmp/PKG-INFO') \
+                    .as_string().splitlines()]
+            try:
+                os.unlink('/tmp/requires.txt')
+            except OSError:
+                pass
+            try:
+                os.unlink('/tmp/PKG-INFO')
+            except OSError:
+                pass
+            os.unlink(tmp_file.name)
+            if metadata:
+                break
+        elif item['packagetype'] == 'bdist_wheel':
+            tmp_file = file_download(item['url'])
+            zip_file = zipfile.ZipFile(tmp_file.name, 'r')
+            for member in zip_file.namelist():
+                if 'METADATA' in member:
+                    metadata = [line.decode('utf-8') for line in zip_file.read(member).splitlines()]
+            os.unlink(tmp_file.name)
+            break
+    return metadata