mmgen/mmgen-wallet
1
Fork 0
Code Releases 28 Wiki Activity

ImmutableAttr,ListItemAttr: minor cleanups

Browse source
This commit is contained in:
The MMGen Project 2020-05-17 20:42:27 +00:00
commit be6a7ef2f5
Signed by: mmgen
GPG key ID: 3F8B1861E32B7DA2
1 changed files with 21 additions and 22 deletions
Download patch file Download diff file Expand all files Collapse all files

43
mmgen/obj.py
View file

@ -223,10 +223,11 @@ class Int(int,Hilite,InitErrors):
def colorize(cls,n,color=True):
return super().colorize(repr(n),color=color)
# For attrs that are always present in the data instance
# Reassignment and deletion forbidden
class ImmutableAttr(object): # Descriptor
class ImmutableAttr: # Descriptor
"""
For attributes that are always present in the data instance
Reassignment and deletion forbidden
"""
ok_dtypes = (str,type,type(None),type(lambda:0))
def __init__(self,dtype,typeconv=True,set_none_ok=False):
@ -241,14 +242,13 @@ class ImmutableAttr(object): # Descriptor
def __get__(self,instance,owner):
return instance.__dict__[self.name]
# forbid all reassignment
def set_attr_ok(self,instance):
def setattr_condition(self,instance):
'forbid all reassignment'
return not self.name in instance.__dict__
def __set__(self,instance,value):
if not self.set_attr_ok(instance):
m = "Attribute '{}' of {} instance cannot be reassigned"
raise AttributeError(m.format(self.name,type(instance)))
if not self.setattr_condition(instance):
raise AttributeError('Attribute {self.name!r} of {type(instance)} instance cannot be reassigned')
if self.set_none_ok and value == None:
instance.__dict__[self.name] = None
elif self.typeconv: # convert type
@ -260,28 +260,27 @@ class ImmutableAttr(object): # Descriptor
elif callable(self.dtype) and type(value) == self.dtype():
instance.__dict__[self.name] = value
else:
m = "Attribute '{}' of {} instance must of type {}"
raise TypeError(m.format(self.name,type(instance),self.dtype))
raise TypeError('Attribute {self.name!r} of {type(instance)} instance must of type {self.dtype}')
def __delete__(self,instance):
m = "Atribute '{}' of {} instance cannot be deleted"
raise AttributeError(m.format(self.name,type(instance)))
# For attrs that might not be present in the data instance
# Reassignment or deletion allowed if specified
class ListItemAttr(ImmutableAttr): # Descriptor
raise AttributeError('Attribute {self.name!r} of {type(instance)} instance cannot be deleted')
class ListItemAttr(ImmutableAttr):
"""
For attributes that might not be present in the data instance
Reassignment or deletion allowed if specified
"""
def __init__(self,dtype,typeconv=True,reassign_ok=False,delete_ok=False):
self.reassign_ok = reassign_ok
self.delete_ok = delete_ok
ImmutableAttr.__init__(self,dtype,typeconv=typeconv)
# return None if attribute doesn't exist
def __get__(self,instance,owner):
"return None if attribute doesn't exist"
try: return instance.__dict__[self.name]
except: return None
def set_attr_ok(self,instance):
def setattr_condition(self,instance):
return getattr(instance,self.name) == None or self.reassign_ok
def __delete__(self,instance):
@ -313,9 +312,9 @@ class MMGenListItem(MMGenObject):
if args:
raise ValueError('Non-keyword args not allowed in {!r} constructor'.format(type(self).__name__))
for k in kwargs:
if kwargs[k] != None:
setattr(self,k,kwargs[k])
for k,v in kwargs.items():
if v != None:
setattr(self,k,v)
# Require all immutables to be initialized. Check performed only when testing.
self.immutable_attr_init_check()