bundling required python dependencies, to make it easier on Tails users

lib/flask/config.py

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+# -*- coding: utf-8 -*-
+"""
+    flask.config
+    ~~~~~~~~~~~~
+
+    Implements the configuration related objects.
+
+    :copyright: (c) 2011 by Armin Ronacher.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import imp
+import os
+import errno
+
+from werkzeug.utils import import_string
+from ._compat import string_types
+
+
+class ConfigAttribute(object):
+    """Makes an attribute forward to the config"""
+
+    def __init__(self, name, get_converter=None):
+        self.__name__ = name
+        self.get_converter = get_converter
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        rv = obj.config[self.__name__]
+        if self.get_converter is not None:
+            rv = self.get_converter(rv)
+        return rv
+
+    def __set__(self, obj, value):
+        obj.config[self.__name__] = value
+
+
+class Config(dict):
+    """Works exactly like a dict but provides ways to fill it from files
+    or special dictionaries.  There are two common patterns to populate the
+    config.
+
+    Either you can fill the config from a config file::
+
+        app.config.from_pyfile('yourconfig.cfg')
+
+    Or alternatively you can define the configuration options in the
+    module that calls :meth:`from_object` or provide an import path to
+    a module that should be loaded.  It is also possible to tell it to
+    use the same module and with that provide the configuration values
+    just before the call::
+
+        DEBUG = True
+        SECRET_KEY = 'development key'
+        app.config.from_object(__name__)
+
+    In both cases (loading from any Python file or loading from modules),
+    only uppercase keys are added to the config.  This makes it possible to use
+    lowercase values in the config file for temporary values that are not added
+    to the config or to define the config keys in the same file that implements
+    the application.
+
+    Probably the most interesting way to load configurations is from an
+    environment variable pointing to a file::
+
+        app.config.from_envvar('YOURAPPLICATION_SETTINGS')
+
+    In this case before launching the application you have to set this
+    environment variable to the file you want to use.  On Linux and OS X
+    use the export statement::
+
+        export YOURAPPLICATION_SETTINGS='/path/to/config/file'
+
+    On windows use `set` instead.
+
+    :param root_path: path to which files are read relative from.  When the
+                      config object is created by the application, this is
+                      the application's :attr:`~flask.Flask.root_path`.
+    :param defaults: an optional dictionary of default values
+    """
+
+    def __init__(self, root_path, defaults=None):
+        dict.__init__(self, defaults or {})
+        self.root_path = root_path
+
+    def from_envvar(self, variable_name, silent=False):
+        """Loads a configuration from an environment variable pointing to
+        a configuration file.  This is basically just a shortcut with nicer
+        error messages for this line of code::
+
+            app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])
+
+        :param variable_name: name of the environment variable
+        :param silent: set to `True` if you want silent failure for missing
+                       files.
+        :return: bool. `True` if able to load config, `False` otherwise.
+        """
+        rv = os.environ.get(variable_name)
+        if not rv:
+            if silent:
+                return False
+            raise RuntimeError('The environment variable %r is not set '
+                               'and as such configuration could not be '
+                               'loaded.  Set this variable and make it '
+                               'point to a configuration file' %
+                               variable_name)
+        return self.from_pyfile(rv, silent=silent)
+
+    def from_pyfile(self, filename, silent=False):
+        """Updates the values in the config from a Python file.  This function
+        behaves as if the file was imported as module with the
+        :meth:`from_object` function.
+
+        :param filename: the filename of the config.  This can either be an
+                         absolute filename or a filename relative to the
+                         root path.
+        :param silent: set to `True` if you want silent failure for missing
+                       files.
+
+        .. versionadded:: 0.7
+           `silent` parameter.
+        """
+        filename = os.path.join(self.root_path, filename)
+        d = imp.new_module('config')
+        d.__file__ = filename
+        try:
+            with open(filename) as config_file:
+                exec(compile(config_file.read(), filename, 'exec'), d.__dict__)
+        except IOError as e:
+            if silent and e.errno in (errno.ENOENT, errno.EISDIR):
+                return False
+            e.strerror = 'Unable to load configuration file (%s)' % e.strerror
+            raise
+        self.from_object(d)
+        return True
+
+    def from_object(self, obj):
+        """Updates the values from the given object.  An object can be of one
+        of the following two types:
+
+        -   a string: in this case the object with that name will be imported
+        -   an actual object reference: that object is used directly
+
+        Objects are usually either modules or classes.
+
+        Just the uppercase variables in that object are stored in the config.
+        Example usage::
+
+            app.config.from_object('yourapplication.default_config')
+            from yourapplication import default_config
+            app.config.from_object(default_config)
+
+        You should not use this function to load the actual configuration but
+        rather configuration defaults.  The actual config should be loaded
+        with :meth:`from_pyfile` and ideally from a location not within the
+        package because the package might be installed system wide.
+
+        :param obj: an import name or object
+        """
+        if isinstance(obj, string_types):
+            obj = import_string(obj)
+        for key in dir(obj):
+            if key.isupper():
+                self[key] = getattr(obj, key)
+
+    def __repr__(self):
+        return '<%s %s>' % (self.__class__.__name__, dict.__repr__(self))