ImportPython Error

pip version conflict

ERROR: pip's dependency resolver does not currently support all features

Traceback

terminal

Traceback (most recent call last):
  File "main.py", line 3, in <module>
    # these package versions have conflicting dependencies.
ERROR: pip's dependency resolver does not currently support all features

What causes this error

Two or more packages require incompatible versions of the same dependency. The dependency resolver cannot find a version that satisfies all constraints.

How to fix it

Check the conflicting requirements in the error output. Try `pip install --upgrade package` for the conflicting packages. Use `pip-compile` or Poetry for better resolution. Use separate virtual environments for incompatible projects.

Code that causes this error

Broken

pip install package-a package-b
# ERROR: Cannot install package-a and package-b because
# these package versions have conflicting dependencies.

Fixed code

Fixed

# Use pip-tools for better resolution:
pip install pip-tools
pip-compile requirements.in
pip-sync requirements.txt

# Or use constraints:
pip install package-a package-b -c constraints.txt

About pip version conflict

A version conflict occurs when pip cannot find a set of package versions that satisfies all dependency requirements simultaneously. Package A might require `numpy>=1.20,<2.0` while package B requires `numpy>=2.0`. Pip's dependency resolver (improved significantly in pip 20.3 with the new resolver) attempts to find compatible versions, but when the constraints are contradictory, it reports a conflict.

The error output lists the conflicting requirements, helping you identify which packages are incompatible. Solutions include upgrading or downgrading specific packages, using different versions of the conflicting packages, creating separate virtual environments for incompatible projects, or using constraint files to pin compatible versions. Tools like `pip-compile` (from pip-tools) and `poetry` handle complex dependency resolution more elegantly than plain pip.

Common scenarios

Installing packages in a different virtual environment than the one in use

Circular imports between modules that depend on each other

Typos in module or package names in import statements

Naming a local file the same as a standard library module