PyMorphy2

Common errors

• DictionaryNotFound: Dictionary for language 'ru' not found. Download it using 'python -m pymorphy2.downloader'.

  cause The `pymorphy2-dicts` package, which contains the necessary morphological dictionaries, is not installed or cannot be found by `pymorphy2`.
  fix Install the dictionary package: `pip install pymorphy2-dicts`.

• ImportError: cannot import name 'MorphAnalyzer' from 'pymorphy2'

  cause This error typically occurs if `pymorphy2` is not properly installed or if there's a naming conflict in your environment (e.g., a local file named `pymorphy2.py`).
  fix Verify installation with `pip show pymorphy2`. If installed, check for conflicting local files or environment path issues. A common mistake is `import pymorphy2.MorphAnalyzer` instead of `from pymorphy2 import MorphAnalyzer`.

• Segmentation fault (core dumped)

  cause Reported in some GitHub issues, particularly with Python 3.7+ and specific installation methods (e.g., `pymorphy2[fast]`). This often indicates low-level C extension issues, possibly related to `DAWG-Python` dependencies.
  fix Try `pip install pymorphy2` without the `[fast]` extra. Ensure all dependencies are up-to-date. If issues persist, consider using a Python version that is known to be stable with `pymorphy2` (e.g., Python 3.8/3.9) or consult the project's GitHub issues for workarounds.

Warnings

• breaking PyMorphy2 versions 0.9.x dropped support for Python 2.6 and Python 3.2-3.4. While Python 2.7 is still technically supported by 0.9.1, explicit support for Python 2.x is planned to be removed in a future v1.0, and Python 3.5+ is recommended. Newer Python versions (3.11, 3.12) report issues.
  Fix: Ensure your project uses Python 3.5 or newer. For Python 3.11/3.12+, be aware of potential compatibility issues or consider community forks.
• gotcha The original `pymorphy2` project is largely unmaintained, with GitHub issues indicating it might be abandoned. This means limited support for newer Python versions, bug fixes, or new features. A community-driven fork (`pymorphy2-fork`) exists to continue development.
  Fix: For active development, consider monitoring or contributing to community forks (e.g., 'pymorphy2-fork' on GitHub) or exploring alternative NLP libraries if long-term maintenance is critical.
• gotcha Directly comparing `tag.POS` or other `tag` attributes with arbitrary string values (e.g., `tag.POS == 'plur'`) can lead to `ValueError` if the string is not a valid grammeme for that attribute. Use `tag.grammemes` for comprehensive checks or refer to documentation for valid grammeme values.
  Fix: Always check against valid grammeme sets or use the provided API correctly. For example, to check for plural, use `tag.number == 'plur'` or `('plur' in tag)`.
• gotcha When installing `pymorphy2` in environments like Jupyter Notebook or Google Colab after the process has started (e.g., `!pip install`), dictionary discovery might fail. Version 0.9.1 fixed this, but older versions or unusual setups might still encounter it.
  Fix: Ensure `pymorphy2` (and `pymorphy2-dicts`) is installed before the main Python process starts, or restart the kernel/runtime after installation. Upgrade to `0.9.1` or later.

Install

• pip install pymorphy2 Install PyMorphy2
• pip install pymorphy2 pymorphy2-dicts Install PyMorphy2 with dictionaries

Imports

• MorphAnalyzer

  from pymorphy2 import MorphAnalyzer

Quickstart

Initializes the MorphAnalyzer and demonstrates basic usage: parsing a word to find its normal form and part of speech, and inflecting it to a different grammatical form. The `pymorphy2-dicts` package must be installed for dictionaries to be found.

import pymorphy2

morph = pymorphy2.MorphAnalyzer()
word = 'стекло'

# Analyze a word
parsed_word = morph.parse(word)[0]
print(f"Original word: {word}")
print(f"Normal form: {parsed_word.normal_form}")
print(f"Part of speech: {parsed_word.tag.POS}")
print(f"All tags: {parsed_word.tag}")

# Inflect a word
inflected = parsed_word.inflect({'gent'})
if inflected: # Check if inflection was successful
    print(f"Inflected to genitive: {inflected.word}")
else:
    print(f"Could not inflect '{word}' to genitive.")