Merge pull request #203 from conda/requirements-spec

Requirements spec

conda_env/cli/main_create.py

@@ -24,6 +24,7 @@
     conda env create -n name
     conda env create vader/deathstar
     conda env create -f=/path/to/environment.yml
+    conda env create -f=/path/to/requirements.txt -n deathstar
 """
 
 

conda_env/specs/__init__.py

@@ -1,12 +1,14 @@
 from .binstar import BinstarSpec
 from .yaml_file import YamlFileSpec
 from .notebook import NotebookSpec
+from .requirements import RequirementsSpec
 from ..exceptions import SpecNotFound
 
 all_specs = [
     BinstarSpec,
     NotebookSpec,
-    YamlFileSpec
+    YamlFileSpec,
+    RequirementsSpec
 ]
 
 

conda_env/specs/requirements.py

@@ -0,0 +1,44 @@
+import os
+
+from .. import env
+
+
+class RequirementsSpec(object):
+    '''
+    Reads depedencies from a requirements.txt file
+    and returns an Environment object from it.
+    '''
+    msg = None
+
+    def __init__(self, filename=None, name=None, **kwargs):
+        self.filename = filename
+        self.name = name
+        self.msg = None
+
+    def _valid_file(self):
+        if os.path.exists(self.filename):
+            return True
+        else:
+            self.msg = "There is no requirements.txt"
+            return False
+
+    def _valid_name(self):
+        if self.name is None:
+            self.msg = "Environment with requierements.txt file needs a name"
+            return False
+        else:
+            return True
+
+    def can_handle(self):
+        return self._valid_file() and self._valid_name()
+
+    @property
+    def environment(self):
+        dependencies = []
+        with open(self.filename) as reqfile:
+            for line in reqfile:
+                dependencies.append(line)
+        return env.Environment(
+            name=self.name,
+            dependencies=dependencies
+        )

conda_env/specs/yaml_file.py

@@ -16,6 +16,9 @@ def can_handle(self):
         except EnvironmentFileNotFound as e:
             self.msg = str(e)
             return False
+        except TypeError:
+            self.msg = "{} is not a valid yaml file.".format(self.filename)
+            return False
 
     @property
     def environment(self):

tests/specs/test_requirements.py

@@ -0,0 +1,28 @@
+import unittest
+
+from .. import utils
+
+from conda_env import env
+from conda_env.specs.requirements import RequirementsSpec
+
+
+class TestRequiremets(unittest.TestCase):
+    def test_no_environment_file(self):
+        spec = RequirementsSpec(name=None, filename='not-a-file')
+        self.assertEqual(spec.can_handle(), False)
+
+    def test_no_name(self):
+        spec = RequirementsSpec(filename=utils.support_file('requirements.txt'))
+        self.assertEqual(spec.can_handle(), False)
+
+    def test_req_file_and_name(self):
+        spec = RequirementsSpec(filename=utils.support_file('requirements.txt'), name='env')
+        self.assertTrue(spec.can_handle())
+
+    def test_environment(self):
+        spec = RequirementsSpec(filename=utils.support_file('requirements.txt'), name='env')
+        self.assertIsInstance(spec.environment, env.Environment)
+        self.assertEqual(
+            spec.environment.dependencies['conda'][0],
+            'flask ==0.10.1'
+        )

tests/support/requirements.txt

@@ -0,0 +1 @@
+flask==0.10.1