devpi-common

4.1.1 · active · verified Thu Apr 16

devpi-common is a utility library providing common functionalities like URL handling, metadata parsing, and archive management. It is primarily used by devpi-server and devpi-client to ensure consistent behavior across the devpi ecosystem. The current version is 4.1.1, with releases often coinciding with major devpi component updates, typically several times a year.

Common errors

```
AttributeError: module 'devpi_common' has no attribute 'URL'
```
cause Attempting to import the `URL` class directly from the `devpi_common` package instead of its specific submodule.

fix Change the import statement to `from devpi_common.url import URL`.
```
TypeError: 'URL' object is not iterable
```
cause Trying to iterate over a `devpi_common.url.URL` object directly, often when expecting it to behave like a list of path segments.

fix Use `url_obj.parts` to get a tuple of path segments if iteration is required, or access specific path components via attributes/methods.
```
Failed to load devpi-server: Incompatible devpi-common version X.Y.Z (expected W.X.Y)
```
cause devpi-server (or devpi-client) was installed with a different version of devpi-common than it expects, leading to runtime incompatibility.

fix Reinstall `devpi-server` (or `devpi-client`) and `devpi-common` together to ensure compatible versions are installed, e.g., `pip install --upgrade devpi-server devpi-client devpi-common`.

Warnings

breaking Python 3.6 support was dropped in devpi-common 4.0.0. Users on Python 3.6 must use an older version.
Fix: Upgrade to Python 3.7 or newer, or pin devpi-common to a version < 4.0.0.
gotcha It is crucial to keep devpi-common's version aligned with devpi-server and devpi-client versions. Mismatched versions can lead to unexpected behavior or errors.
Fix: Always install devpi-common at the same time or with the same version constraints as devpi-server and devpi-client, or ensure they are from the same release train. For example, `pip install devpi-server devpi-client devpi-common`.
gotcha The `URL` object from `devpi_common.url` is not directly iterable. Attempting to iterate over it (e.g., in a `for` loop expecting path segments) will raise a `TypeError`.
Fix: Access specific parts of the URL using its attributes like `.path`, `.parts`, or methods like `.joinpath()`. To get path segments, use `url_obj.parts`.

Install

pip install devpi-common Install latest version

Imports

URL
wrong:
```
from devpi_common import URL
```
correct:
```
from devpi_common.url import URL
```
URL is located in the devpi_common.url submodule, not directly under devpi_common.

get_metadata

from devpi_common.metadata import get_metadata

archive_file

from devpi_common.archive import archive_file

Plugin
```
from devpi_common.plugin import Plugin
```

Quickstart

This quickstart demonstrates how to use the `devpi_common.url.URL` object for parsing, manipulating, and composing URLs, which is one of the core utilities provided by the library.

from devpi_common.url import URL

# Create a URL object
url_obj = URL('https://pypi.org/project/devpi-common/4.1.1/')
print(f"Original URL: {url_obj}")

# Access parts of the URL
print(f"Scheme: {url_obj.scheme}")
print(f"Netloc: {url_obj.netloc}")
print(f"Path: {url_obj.path}")

# Join paths
new_url = url_obj.joinpath('../pypi')
print(f"Joined URL: {new_url}")

# Create a URL from components
composed_url = URL(scheme='http', netloc='localhost:3141', path='/root/pypi/')
print(f"Composed URL: {composed_url}")

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