0x1949 Team - FAZEMRX - MANAGER
Edit File: schema.py
"""A schema system. Yes. Another one!""" from twisted.python.compat import iteritems, unicode, long class InvalidError(Exception): """Raised when invalid input is received.""" pass class Constant(object): """Something that must be equal to a constant value.""" def __init__(self, value): self.value = value def coerce(self, value): if isinstance(self.value, str) and isinstance(value, bytes): try: value = value.decode() except UnicodeDecodeError: pass if value != self.value: raise InvalidError("%r != %r" % (value, self.value)) return value class Any(object): """Something which must apply to any of a number of different schemas. @param schemas: Other schema objects. """ def __init__(self, *schemas): self.schemas = schemas def coerce(self, value): """ The result of the first schema which doesn't raise L{InvalidError} from its C{coerce} method will be returned. """ for schema in self.schemas: try: return schema.coerce(value) except InvalidError: pass raise InvalidError("%r did not match any schema in %s" % (value, self.schemas)) class Bool(object): """Something that must be a C{bool}.""" def coerce(self, value): if not isinstance(value, bool): raise InvalidError("%r is not a bool" % (value,)) return value class Int(object): """Something that must be an C{int} or C{long}.""" def coerce(self, value): if not isinstance(value, (int, long)): raise InvalidError("%r isn't an int or long" % (value,)) return value class Float(object): """Something that must be an C{int}, C{long}, or C{float}.""" def coerce(self, value): if not isinstance(value, (int, long, float)): raise InvalidError("%r isn't a float" % (value,)) return value class Bytes(object): """A binary string. If the value is a Python3 str (unicode), it will be automatically encoded. """ def coerce(self, value): if isinstance(value, bytes): return value if isinstance(value, str): return value.encode() raise InvalidError("%r isn't a bytestring" % value) class Unicode(object): """Something that must be a C{unicode}. If the value is a C{str}, it will automatically be decoded. @param encoding: The encoding to automatically decode C{str}s with. """ def __init__(self, encoding="utf-8"): self.encoding = encoding def coerce(self, value): if isinstance(value, bytes): try: value = value.decode(self.encoding) except UnicodeDecodeError as e: raise InvalidError("%r can't be decoded: %s" % (value, str(e))) if not isinstance(value, unicode): raise InvalidError("%r isn't a unicode" % (value,)) return value class List(object): """Something which must be a C{list}. @param schema: The schema that all values of the list must match. """ def __init__(self, schema): self.schema = schema def coerce(self, value): if not isinstance(value, list): raise InvalidError("%r is not a list" % (value,)) new_list = list(value) for i, subvalue in enumerate(value): try: new_list[i] = self.schema.coerce(subvalue) except InvalidError as e: raise InvalidError( "%r could not coerce with %s: %s" % (subvalue, self.schema, e)) return new_list class Tuple(object): """Something which must be a fixed-length tuple. @param schema: A sequence of schemas, which will be applied to each value in the tuple respectively. """ def __init__(self, *schema): self.schema = schema def coerce(self, value): if not isinstance(value, tuple): raise InvalidError("%r is not a tuple" % (value,)) if len(value) != len(self.schema): raise InvalidError("Need %s items, got %s in %r" % (len(self.schema), len(value), value)) new_value = [] for schema, value in zip(self.schema, value): new_value.append(schema.coerce(value)) return tuple(new_value) class KeyDict(object): """Something which must be a C{dict} with defined keys. The keys must be constant and the values must match a per-key schema. @param schema: A dict mapping keys to schemas that the values of those keys must match. """ def __init__(self, schema, optional=None): if optional is None: optional = [] self.optional = set(optional) self.schema = schema def coerce(self, value): new_dict = {} if not isinstance(value, dict): raise InvalidError("%r is not a dict." % (value,)) for k, v in iteritems(value): if k not in self.schema: raise InvalidError("%r is not a valid key as per %r" % (k, self.schema)) try: new_dict[k] = self.schema[k].coerce(v) except InvalidError as e: raise InvalidError( "Value of %r key of dict %r could not coerce with %s: %s" % (k, value, self.schema[k], e)) new_keys = set(new_dict.keys()) required_keys = set(self.schema.keys()) - self.optional missing = required_keys - new_keys if missing: raise InvalidError("Missing keys %s" % (missing,)) return new_dict class Dict(object): """Something which must be a C{dict} with arbitrary keys. @param key_schema: The schema that keys must match. @param value_schema: The schema that values must match. """ def __init__(self, key_schema, value_schema): self.key_schema = key_schema self.value_schema = value_schema def coerce(self, value): if not isinstance(value, dict): raise InvalidError("%r is not a dict." % (value,)) new_dict = {} for k, v in value.items(): new_dict[self.key_schema.coerce(k)] = self.value_schema.coerce(v) return new_dict