added a flask venv

2019-01-19 13:23:37 +01:00
parent cbd3a55746
commit a1a8bca34b
961 changed files with 129021 additions and 0 deletions
@@ -0,0 +1,54 @@
+import os
+
+
+class UndefinedValueError(Exception):
+    pass
+
+
+class Undefined(object):
+    """Class to represent undefined type. """
+    pass
+
+
+# Reference instance to represent undefined values
+undefined = Undefined()
+
+
+def _cast_boolean(value):
+    """
+    Helper to convert config values to boolean as ConfigParser do.
+    """
+    _BOOLEANS = {'1': True, 'yes': True, 'true': True, 'on': True,
+                 '0': False, 'no': False, 'false': False, 'off': False, '': False}
+    value = str(value)
+    if value.lower() not in _BOOLEANS:
+        raise ValueError('Not a boolean: %s' % value)
+
+    return _BOOLEANS[value.lower()]
+
+
+def getenv(option, default=undefined, cast=undefined):
+    """
+    Return the value for option or default if defined.
+    """
+
+    # We can't avoid __contains__ because value may be empty.
+    if option in os.environ:
+        value = os.environ[option]
+    else:
+        if isinstance(default, Undefined):
+            raise UndefinedValueError('{} not found. Declare it as envvar or define a default value.'.format(option))
+
+        value = default
+
+    if isinstance(cast, Undefined):
+        return value
+
+    if cast is bool:
+        value = _cast_boolean(value)
+    elif cast is list:
+        value = [x for x in value.split(',') if x]
+    else:
+        value = cast(value)
+
+    return value