Here’s how to adapt the accepted answer to the question Abstract Enum Class using ABCMeta and EnumMeta to create the kind of abstract Enum class you want: from abc import abstractmethod, ABC, ABCMeta from enum import auto, Flag, EnumMeta class ABCEnumMeta(ABCMeta, EnumMeta): def __new__(mcls, *args, **kw): abstract_enum_cls = super().__new__(mcls, *args, **kw) # Only check abstractions … Read more
The warning is raised if you use super that relies on __class__ being available or reference __class__ inside the class body. What the text essentially says is that, this is needed if you define a custom meta-class and tamper with the namespace you get before passing it up to type.__new__. You’ll need to be careful … Read more
No, ‘snow’ is a string literal, an expression that produces a string value. snow would be a variable name (note the lack of quotes). Compare: >>> ‘snow’ ‘snow’ >>> snow Traceback (most recent call last): File “<stdin>”, line 1, in <module> NameError: name ‘snow’ is not defined >>> snow = 42 >>> snow 42 >>> … Read more
PEP 487 sets out to take two common metaclass usecases and make them more accessible without having to understand all the ins and outs of metaclasses. The two new features, __init_subclass__ and __set_name__ are otherwise independent, they don’t rely on one another. __init_subclass__ is just a hook method. You can use it for anything you … Read more
You can’t. Backslashes cannot appear inside the curly braces {}; doing so results in a SyntaxError: >>> f'{\}’ SyntaxError: f-string expression part cannot include a backslash This is specified in the PEP for f-strings: Backslashes may not appear inside the expression portions of f-strings, […] One option is assinging ‘\n’ to a name and then … Read more
I don’t think formatted string literals allowing nesting (by nesting, I take it to mean f'{f”..”}’) is a result of careful consideration of possible use cases, I’m more convinced it’s just allowed in order for them to conform with their specification. The specification states that they support full Python expressions* inside brackets. It’s also stated … Read more
\ is the escape character in Python string literals. For example if you want to put a tab character in a string you would do: >>> print(“foo \t bar”) foo bar If you want to put a literal \ in a string you have to use \\: >>> print(“foo \\ bar”) foo \ bar Or … Read more
I followed the below steps for python3.6 installation in ubuntu 14.04 and virtualenv pip installs works fine. Python 3.6 Installation: sudo apt-get install python3-dev libffi-dev libssl-dev wget https://www.python.org/ftp/python/3.6.0/Python-3.6.0.tgz tar xvf Python-3.6.0.tgz cd Python-3.6.0 ./configure –enable-optimizations make -j8 sudo make altinstall python3.6 If seeing the following error — zipimport.ZipImportError: can’t decompress data; zlib not available make: … Read more
To get the latest PySide, install one of the official binary wheels from PyPI which includes a bundled Qt and is therefore fully portable. For Qt5 – [Python 2.7 / Python >= 3.5]: pip install pyside2 For Qt6 – [Python >= 3.6]: pip install pyside6 The information presented in the section below relates to PySide-1.2/Qt4 … Read more
When packaged to a single file with PyInstaller, running the .exe will unpack everything to a folder in your TEMP directory, run the script, then discard the temporary files. The path of the temporary folder changes with each running, but a reference to its location is added to sys as sys._MEIPASS. To make use of … Read more