old_readme.md

lasio

Read/write well data from Log ASCII Standard (LAS) files.

This is a Python package to read and write Log ASCII Standard (LAS) files, used for borehole/well data (e.g. geophysical/geological/petrophysical logs). It is compatible with versions 1.2 and 2.0 of the LAS file specification, published by the Canadian Well Logging Society. In principle it is designed to read as many types of LAS files as possible, including ones containing common errors or non-compliant formatting.

It is written entirely in Python and works on any platform. It requires:

• the small third-party packages namedlist and ordereddict
• numpy.

Install

To install from PyPI use:

$ pip install lasio

If necessary this will download and install the package dependencies.

Alternatively if you would like the latest version (which may contain bugs and errors) make sure you have setuptools and git installed and then:

$ git clone https://github.com/kinverarity1/lasio.git
$ cd lasio
$ python setup.py develop 

How to use

Look at the example IPython notebooks here. More detailed examples are coming.

Opening LAS files

From a filename:

>>> import lasio
>>> l = lasio.read("example.las")

Or a URL:

>>> l = lasio.read("http://someplace.com/example.las")

Getting data

The curve data are available as items:

>>> l["ILD"]
[145, 262, 272, ...]

Or you can iterate through the curves:

>>> for c in l.curves:
...     print c.mnemonic, c.unit, c.data
DEPT m [0, 0.05, 0.10, ...] 
ILD mS/m [145, 262, 272, ...]

Character encodings

Three options:

1. Do nothing and hope for no errors.

2. Specify the encoding (it uses codecs.open internally):

   >>> l = lasio.read("example.las", encoding="windows-1252")

3. Install a third-party package like cChardet (faster) or chardet (slower) to automatically detect the character encoding. If these packages are installed this code will use the fastest option:

   >>> l = lasio.read("example.las", autodetect_encoding=True)

Note that by default autodetect_encoding=False.

Development

• 0.7 (2015-08-08) - all tests passing on Python 2.6 through 3.4
• 0.6 (2015-08-05) - bugfixes and renamed from las_reader to lasio
• 0.5 (2015-08-01) - Improvements to writing LAS files
• 0.4 (2015-07-26) - Improved handling of character encodings, other internal improvements
• 0.3 (2015-07-23) - Added Python 3 support, now reads LAS 1.2 and 2.0
• 0.2 (2015-07-08) - Tidied code and published on PyPI

Contributions

Contributions are very welcome. Please fork kinverarity1/lasio on GitHub and submit a PR request containing any changes you have made.

Suggested improvements, bug reports, shortcomings, desirable features, examples of LAS files which do not load as you expected, are all also welcome either via GitHub or by email.

Thanks to the following people in chronological order for their help:

• @VelizarVESSELINOV
• @diverdude

License

The code is freely available for any kind of use or modification under the MIT License.