Some python tricks 1 - custom exceptions, dataclasses, dot accessing to dict and annotations
Теги:
translate in Python to transliterate Cyrillic
How call ipython from virtualenv
python -m IPython
Proper way to declare custom exceptions in modern Python
class ValidationError(Exception):
def __init__(self, message, errors):
# Call the base class constructor with the parameters it needs
super().__init__(message)
# Now for your custom code...
self.errors = errors
Accessing dict keys like an attribute
example:
class Map(dict):
"""
Example:
m = Map({'first_name': 'Eduardo'}, last_name='Pool', age=24, sports=['Soccer'])
"""
def __init__(self, *args, **kwargs):
super(Map, self).__init__(*args, **kwargs)
for arg in args:
if isinstance(arg, dict):
for k, v in arg.iteritems():
self[k] = v
if kwargs:
for k, v in kwargs.iteritems():
self[k] = v
def __getattr__(self, attr):
return self.get(attr)
def __setattr__(self, key, value):
self.__setitem__(key, value)
def __setitem__(self, key, value):
super(Map, self).__setitem__(key, value)
self.__dict__.update({key: value})
def __delattr__(self, item):
self.__delitem__(item)
def __delitem__(self, key):
super(Map, self).__delitem__(key)
del self.__dict__[key]
dotmap Dot access dictionary with dynamic hierarchy creation and ordered iteration
How to annotate a type that’s a class object (instead of a class instance)
from typing import Type
class Foo: ...
class Bar(Foo): ...
class Baz: ...
some_class: Type[Foo]
some_class = Foo # ok
some_class = Bar # ok
some_class = Baz # error
some_class = Foo() # error
Types annotations for classes with dynamic attribute names
example that not solve problem
How to return dictionary keys as a list in Python
>>> newdict = {1:0, 2:0, 3:0}
>>> [*newdict]
[1, 2, 3]
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