add parameter to specify python interpreter and commands to create and test virtual environments

cookiecutter.json

@@ -5,5 +5,6 @@
     "description": "A short description of the project.",
     "year": "2016",
     "open_source_license": ["MIT", "BSD", "Not open source"],
-    "s3_bucket": "[OPTIONAL] your-bucket-for-syncing-data (do not include 's3://')"
+    "s3_bucket": "[OPTIONAL] your-bucket-for-syncing-data (do not include 's3://')",
+    "python_interpreter": ["python", "python3"]
 }

{{ cookiecutter.repo_name }}/Makefile

@@ -5,13 +5,15 @@
 #################################################################################
 
 BUCKET = {{ cookiecutter.s3_bucket }}
+PROJECT_NAME = {{ cookiecutter.repo_name }}
+PYTHON_INTERPRETER = {{ cookiecutter.python_interpreter }}
 
 #################################################################################
 # COMMANDS                                                                      #
 #################################################################################
 
 ## Install Python Dependencies
-requirements:
+requirements: test_environment
 	pip install -q -r requirements.txt
 
 ## Make Dataset
@@ -34,6 +36,15 @@ sync_data_to_s3:
 sync_data_from_s3:
 	aws s3 sync s3://$(BUCKET)/data/ data/
 
+## Set up python interpreter environment
+setup_environment:
+	source /usr/local/bin/virtualenvwrapper.sh; mkvirtualenv $(PROJECT_NAME) --python=$(PYTHON_INTERPRETER)
+	@echo ">>> Activate virtualenv with:\nworkon $(PROJECT_NAME)"
+
+## Test python environment is setup correctly
+test_environment:
+	python test_environment.py
+
 #################################################################################
 # PROJECT RULES                                                                 #
 #################################################################################

{{ cookiecutter.repo_name }}/test_environment.py

@@ -0,0 +1,24 @@
+import sys
+
+REQUIRED_PYTHON = "{{ cookiecutter.python_interpreter }}"
+
+
+def main():
+    system_major = sys.version_info.major
+    if REQUIRED_PYTHON == "python":
+        required_major = 2
+    elif REQUIRED_PYTHON == "python3":
+        required_major = 3
+    else:
+        raise ValueError("Unrecognized python interpreter: {}".format(
+            REQUIRED_PYTHON))
+
+    if system_major != required_major:
+        raise TypeError("This project requires Python {}. Found: {}".format(
+            required_major, sys.version))
+    else:
+        print(">>> Development environment passes all tests!")
+
+
+if __name__ == '__main__':
+    main()