Check python-version (>=2.7.9) on startup

README.rst

@@ -50,8 +50,8 @@ Notes
 
 Pyethapp runs on Python 2.7. If you don't know how to install an
 up-to-date version of Python, have a look
-`here <https://wiki.python.org/moin/BeginnersGuide>`__. It is always
-advised to install system-dependecies with the help of a package manager
+`here <https://wiki.python.org/moin/BeginnersGuide>`__. The minimum required version is ``2.7.9``. 
+It is always advised to install system-dependecies with the help of a package manager
 (e.g. *homebrew* on Mac OS X or *apt-get* on Debian).
 
 Please install a *virtualenv* environment for a comfortable Pyethapp

pyethapp/app.py

@@ -32,8 +32,10 @@
 from pyethapp.utils import merge_dict, load_contrib_services, FallbackChoice
 import utils
 
-log = slogging.get_logger('app')
+# minimum required python version
+PY_VERSION = '2.7.9'
 
+log = slogging.get_logger('app')
 
 services = [DBService, AccountsService, NodeDiscovery, PeerManager, ChainService, PoWService,
             JSONRPCServer, IPCRPCServer, Console]
@@ -86,6 +88,12 @@ def app(ctx, profile, alt_config, config_values, alt_data_dir, log_config, boots
     # configure logging
     slogging.configure(log_config, log_json=log_json, log_file=log_file)
 
+    # check if minimum required python version
+    required_version = tuple(map(int, PY_VERSION.split('.')))
+    if sys.version_info < required_version:
+        log.fatal('python version must be at least {}'.format(PY_VERSION))
+        sys.exit(1)
+
     # data dir default or from cli option
     alt_data_dir = os.path.expanduser(alt_data_dir)
     data_dir = alt_data_dir or konfig.default_data_dir