I have a python package defined via __init__.py in a folder named python_utils that has many python scripts in it.
python_utils/
__init__.py
print_pretty.py
script_1.py
...
For convenience this __init__.py imports all of them using:
from .pretty_print import pretty_print
from .scritp_1 import func1
from .script_2 import func2
....
The problem I have is that some of the python scripts depend on packages that may not be available at run time. So when I try to import a very trivial function from the package (from python_utils import print_pretty), it fails because of the dependencies the other scripts have. I also tried to import directly with from python_utils.print_pretty import print_pretty same problem. I can get rid of the __init__.py to solve the problem, but it saves me a lot of typing when importing packages. Is there a way I can import only pretty_print without getting the dependencies from the other scripts?
Related
I'm developing a GUI app as a Python package and have an issue. If I install the package in editable mode with pip install -e ., then it works fine, but if I try to just pip install it normally, then when I run it, I get a circular import error.
My (simplified) project structure looks like this:
package/
__init__.py
__main__.py
gui/
main_window.py
dialogs/
misc.py
typing_/
__init__.py
package/typing_/__init__.py contains type aliases which are used all over the codebase. Many files have from package.typing_ import AliasName without issue, although this may be because these imports come last, so the package fails to import before reaching them.
The main circular import error comes from package/gui/dialogs/misc.py, which contains an AboutDialog class. This class wants package.__version__, which is defined in package/__init__.py, to display the version in the about box.
I've tried import package and using package.__version__, as well as from package import __version__, but neither of them work and both result in a circular import error.
It's not crucial to the development, because the package still works in editable mode, but there's clearly some bad design going on and I want to fix it.
tl;dr - My python package requires import package.package instead of working with just import package. How do I get it to work with the latter?
I am trying to set up my first python package and am running into some issues with the import part of the process.
My python package file setup looks like this on my computer:
my-package
- build
- dist
- package
- package.egg-info
- LICENSE
- README.md
- Setup.py
Inside package is the following:
__init__.py
package.py
__init__.py reads name = 'package', and package.py contains all of the content of the package.
EDIT: I have attempted using various different versions of __init__.py, including adding import package, import package.package, or import package.package as package below the line name = 'package', but all of resulted in the same issue.
Using the Packaging Python Projects tutorial, I've been able to get my package upload to TestPyPi, but when I install the package to my computer, none of the functions/methods are available, and when I run "import package" and do help(package), I get the following:
Help on package package:
NAME
package
PACKAGE CONTENTS
package
DATA
name = 'package'
FILE
url/to/package
When I run import package.package and help(package), I can access the methods/functions, and get the expected help text for the package's content.
My question is, how to I configure the package file on my computer in such a way that once it is upload to TestPyPi and then downloaded, import package works, instead of needing to run import package.package?
When you write import package, you can access names in package/__init__.py as package.foo.
So, inside __init__.py, if you import all the necessary functions/variables/etc from package.py, those names will be visible to clients that just import package.
So, if you have this in package/__init__.py:
from .package import (foo, bar, baz)
Then in your other code you can do this:
from package import foo
And you dont have to worry about from package.package import foo.
I have the following directory structure:
app/
bin/
script1.py
script2.py
lib/
module1/
__init__.py
module1a.py
module1b.py
__init__.py
module2.py
Dockerfile
My problem is that I want to execute script1.py and script2.py, but inside those scripts, I want to import the modules in lib/.
I run my scripts from the root app/ directory (i.e. adjacent to Dockerfile) by simply executing python bin/script1.py. When I import modules into my scripts using from lib.module1 import module1a, I get ImportError: No module named lib.module1. When I try to import using relative imports, such as from ..lib.module1 import module1a, I get ValueError: Attempted relative import in non-package.
When I simply fire up the interpreter and run import lib.module1 or something, I have no issues.
How can I get this to work?
In general, you need __init__.py under app and bin, then you can do a relative import, but that expects a package
If you would structure your python code as python package (egg/wheel) then you could also define an entry point, that would become your /bin/ file post install.
here is an example of a package - https://python-packaging.readthedocs.io/en/latest/minimal.html
and this blog explains entry points quite well - https://chriswarrick.com/blog/2014/09/15/python-apps-the-right-way-entry_points-and-scripts/
if so, that way you could just do python setup.py install on your package and then have those entry points available within your PATH, as part of that you would start to structure your code in a way that would not create import issues.
You can add to the Python path at runtime in script1.py:
import sys
sys.path.insert(0, '/path/to/your/app/')
import lib.module1.module1a
you have to add current dir to python path.
use export in terminal
or sys.path.insert in your python script both are ok
I am new to python and i am having some issues with packages and imports.
My structure is as follows:
src/
base/
packcore/
__init__.py
utils/
__init__.py
util_1.py
util_2.py
helpers/
__init__.py
helper_1.py
helper_2.py
some_script.py
app.py
packcore is an external package that has been installed using pip and put into the --target=base.
some of the helpers in the packcore uses some of the utils.
From app.py i want to be able to import a helper/util.
But when i use from base.packcore.utils import some_util i get an error saying that no module named packcore from inside the helper/util
and if i do from packcore.utils import some_util i get an error no module named packcorefrom theapp.py`
help would be much appreciated :)
If you add an __init__.py to base/, you can make it a Python package to import from. You also need to make the parent a package (Which is currently called src) so it is actually a sibling module, rather than many isolated modules.
From there, you can either do an absolute import from the main package:
from src.base.packcore.helpers import helper_1
Or relative (Assuming you are in some_script.py or app.py):
from .base.packcore.helpers import helper_1
My directory structure is:
package_name/
__init__.py
script.py
time.py
I'm trying to import time (the built-in package) from script.py. however, my sibling time.py is hooked up instead.
What's the syntax of importing a package globally? (e.g. importing from /usr/lib/python2.7/dist-packages)
In c# i know it as the global:: prefix, what's the equivalent in python?
Be more explicit with your imports.
import time will import the python time module.
from mypackage import time will import the time module in your mypackage package.
import time should never import mypackage.time
That said, don't shadow python built-in names, it's a bad habit and leads to these headaches later.
A Hack
While there are other ways, i adopted this one
1) add a sub package
Let's call it utils. your directory tree should look like:
package_name/
__init__.py
script.py
time.py
utils/
__init__.py
2) create a file named builtin.py under that package
This should be the contents of builtin.py :
import time
time = time
3) use it!
Import time in script.py using this:
from utils.builtin import time
time.sleep(5)