python-import

问题 I'm trying to get myself familiar with importlib hooks. I want to implement an ability to directly import non-pythonic files written in other language, and maintain source maps, so raising SyntaxError s with line numbers will still give meaningful stacktraces. My approach to loading foreign files is assembling Pythonic source, then compiling it and executing it in the desired context. I've read in the documentation that implementing importlib.abc.SourceLoader seems to be my choice — however,

问题 I've seen the term __loader__ floating around some Python files and I can't find any documentation on it aside from a few brief descriptions about it's purpose, but they still don't provide enough information for me to get a good understanding of it. All I know is that it has something to do with importing modules, other than that I'm completely at a loss. What does it do? When is it used? How can I use it if at all? 回答1: What is __loader__ ? __loader__ is an attribute that is set on an

问题 I've seen the term __loader__ floating around some Python files and I can't find any documentation on it aside from a few brief descriptions about it's purpose, but they still don't provide enough information for me to get a good understanding of it. All I know is that it has something to do with importing modules, other than that I'm completely at a loss. What does it do? When is it used? How can I use it if at all? 回答1: What is __loader__ ? __loader__ is an attribute that is set on an

问题 I've seen the term __loader__ floating around some Python files and I can't find any documentation on it aside from a few brief descriptions about it's purpose, but they still don't provide enough information for me to get a good understanding of it. All I know is that it has something to do with importing modules, other than that I'm completely at a loss. What does it do? When is it used? How can I use it if at all? 回答1: What is __loader__ ? __loader__ is an attribute that is set on an

问题 I always thought, doing from x import y and then directly use y , or doing import x and later use x.y was only a matter of style and avoiding naming conflicts. But it seems like this is not always the case. Sometimes from ... import ... seems to be required : Python 3.7.5 (default, Nov 20 2019, 09:21:52) [GCC 9.2.1 20191008] on linux Type "help", "copyright", "credits" or "license" for more information. >>> import PIL >>> PIL.__version__ '6.1.0' >>> im = PIL.Image.open("test.png") Traceback

问题 First of all, there are a bunch of solutions on stackoverflow regarding this but from the ones I tried none of them is working. I am working on a remote machine (linux). I am prototyping within the dir-2/module_2.py file using an ipython interpreter. Also I am trying to avoid using absolute paths as the absolute path in this remote machine is long and ugly, and I want my code to run on other machines upon download. My directory structure is as follows: /project-dir/ -/dir-1/ -/__ init__.py -

问题 I have installed a certain python package (netCDF4), which contains compiled code (extension module). I am running Anaconda and python 3.6 under Windows 10 (x64). When importing the module from console, I get the following error: In [1]: import netCDF4 --------------------------------------------------------------------------- ImportError Traceback (most recent call last) <ipython-input-1-9588a3d4fb24> in <module>() ----> 1 import netCDF4 C:\Program Files\Anaconda3\lib\site-packages\netCDF4\_

问题 I have installed a certain python package (netCDF4), which contains compiled code (extension module). I am running Anaconda and python 3.6 under Windows 10 (x64). When importing the module from console, I get the following error: In [1]: import netCDF4 --------------------------------------------------------------------------- ImportError Traceback (most recent call last) <ipython-input-1-9588a3d4fb24> in <module>() ----> 1 import netCDF4 C:\Program Files\Anaconda3\lib\site-packages\netCDF4\_

问题 I have the following directory structure inside a virtualenv : /dir_a/dir_b/__init__.py /dir_a/dir_b/module_1.py /dir_a/dir_b/module_2.py /dir_a/dir_c/__init__.py /dir_a/dir_c/module_3.py /dir_a/__init__.py /dir_a/module_4.py Inside module_4.py , I can successfully import module_1.py , module_2.py and module_3.py . On the other hand, I cannot import module_4.py within module_3.py (e.g. import dir_a.module_4 ). It complains: "No module named dir_a.module_4" What am I missing here? Do I need to

问题 I am making tests for my code, but I'm facing a strange import error. Notes: I am using VSCode version: 1.46.1 PYTHONPATH is set to project's root Folder structure is this: -app.py -models ---language.py ---category.py -my_tests ---unit ------models ---------category_test.py ---------language_test.py In category_test, I do import "Category" class by using: from models.category import Category In language_test, I do import "Language" class by using: from models.language import Language In