A pure Python implementation of the SwissTopo LandesVermessung 1995 (LV95) and -1903 (LV03) projections and conversions from and to WGS84 or Bessel1841 geodetic lat-, longitude and height.
PyChLV includes 4 transformer classes ChLVa, ChLVe, ChLVr and ChLV. Each
class provides a forward method to convert a geodetic lat-, longitude and height to local
Y, X and Swiss h' coordinates and a reverse method to convert local coordinates
to geodetic lat-, longitude and height.
For further details see the documentation.
To install pychlv, type python[3] -m pip install pychlv or python[3] -m easy_install pychlv
in a terminal or command window.
Alternatively, download pychlv-yy.m.d.tar.gz from PyPI or GitHub, unzip the downloaded file,
cd to directory pychlv-yy.m.d and type python[3] setup.py install.
To run the pychlv tests, type python[3] test/run.py or type python[3] test/unitTestSuite.py
before or after installation.
Installation of Python package pygeodesy is required, version 26.7.7 or newer. Type
python[3] -m pip install -r requirements.txt to install.
In addition to the pychlv package, the pychlv distribution file contain the tests, the test
results (on macOS only) and the complete documentation generated by Epydoc using command line:
epydoc --html --no-private --no-source --name=pychlv --url=... -v pychlv.
The tests ran with Python 3.14.6, 2.7.18 and with PyPy 7.3.17 (Python 3.10.14), all with pygeodesy 26.5.26 and on macOS 26.5.2 Tahoe in 64-bit. The results of those tests are included in the distribution file.
Python 3.14.6 and PyPy 7.3.17 run on Apple M4 (arm64), natively. Python 2.7.18 runs on
Intel (x86_64) or Intel emulation ("arm64_x86_64", see function pychlv.machine).
Test coverage has been measured with coverage 7.14.0 using Python 3.14.6. The complete coverage report in HTML and a PDF summary are included in the distribution file.
The tests also ran with Python 3.14.6 on Windows 2019Server and with Python 3.13.3 on Windows 11, both in 64-bit only.
All Python source code has been statically checked with Ruff using Python 3.13.12 and with PyChecker, PyFlakes, PyCodeStyle (formerly Pep8) and McCabe using Python 2.7.18, both in 64-bit on macOS 26.5.2 Tahoe only.
Last updated: July 17, 2026.
Copyright (C) 2026-2026 -- mrJean1 at Gmail -- All Rights Reserved.
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
