How to Install `pyasn1-modules` in Python

v0.4.2 CLI & Utilities Python >=3.8 BSD

A collection of ASN.1-based protocols modules

Install pip install pyasn1-modules

What is pyasn1-modules?

A collection of ASN.1-based protocols modules

The package contains a collection of ASN.1 data structures expressed as Python classes based on pyasn1 data model.

If ASN.1 module you need is not present in this collection, try using Asn1ate tool that compiles ASN.1 documents into pyasn1 code.

NOTE: The package is now maintained by Christian Heimes and Simon Pichugin in project

Documentation → PyPI page → Author: Ilya Etingof

Quick Start

Minimal example to get started with pyasn1-modules:

import pyasn1_modules

print(pyasn1_modules.__version__)

Installation

pip (standard)

pip install pyasn1-modules

Virtual environment (recommended)

python -m venv venv
source venv/bin/activate   # Windows: venv\Scripts\activate
pip install pyasn1-modules

pip3

pip3 install pyasn1-modules

conda

conda install -c conda-forge pyasn1-modules

Poetry

poetry add pyasn1-modules

Dependencies

Installing pyasn1-modules will also install these packages:

pyasn1

Verify the Installation

After installing, confirm the package is available:

python -c "import pyasn1_modules; print(pyasn1_modules.__version__)"

If this prints a version number, installation succeeded. If you see a ModuleNotFoundError, see the errors section below.

Installation Errors

Common errors when installing pyasn1-modules with pip.

ModuleNotFoundError: No module named 'pyasn1_modules'

Cause: The package is not installed in the current Python environment.

Fix: Run pip install pyasn1-modules. If using a virtual environment, ensure it is activated first.

ModuleNotFoundError: No module named 'pyasn1_modules' (installed but still failing)

Cause: pip installed the package into a different Python than the one running your script.

Fix: Use python -m pip install pyasn1-modules to install into the interpreter you are running.

ImportError: cannot import name 'X' from 'pyasn1_modules'

Cause: The function or class does not exist in the installed version.

Fix: Check the version with pip show pyasn1-modules and upgrade with pip install --upgrade pyasn1-modules.

pip: command not found

Cause: pip is not in PATH or Python was not added to PATH during installation.

Fix: Try python -m pip install pyasn1-modules. On macOS/Linux try pip3.

PermissionError: [Errno 13] Permission denied

Cause: No write access to the system Python package directory.

Fix: Use a virtual environment, or add --user: pip install --user pyasn1-modules

SSL: CERTIFICATE_VERIFY_FAILED

Cause: pip cannot verify PyPI's SSL certificate — common behind corporate proxies.

Fix: Try: pip install --trusted-host pypi.org --trusted-host files.pythonhosted.org pyasn1-modules

Recent Releases

Version	Released
`0.4.2` latest	2025-03-28
`0.4.1`	2024-09-10
`0.4.0`	2024-03-26
`0.3.0`	2023-04-20
`0.2.8`	2020-01-09

Full release history on PyPI →

Manage pyasn1-modules

Upgrade to latest version

pip install --upgrade pyasn1-modules

Install a specific version

pip install pyasn1-modules==0.4.2

Uninstall

pip uninstall pyasn1-modules

Check what is installed

pip show pyasn1-modules

Last updated: 2026-04-11 • Data from PyPI

How to Install pyasn1-modules in Python