lasio

library0.32pypypi✓ verified 83d ago

The `lasio` library (version 0.32) provides robust tools for reading and writing well data from Log ASCII Standard (LAS) files, supporting both LAS 1.2 and 2.0 specifications. It is actively maintained with regular updates for bug fixes and feature enhancements, typically releasing new minor versions a few times a year.

data database

pip install lasio

package ↗

INSTALL

IMPORT

SIG · LASIO

lasio

datapythonv0.32

Install

3.8s avg

Import

408ms

Disk

89MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v0.32 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.910 runs

installs and imports cleanly · install 0.0s · import 0.406s · 89.6MB

glibc

py 3.10–3.910 runs

installs and imports cleanly · install 3.8s · import 0.410s · 86MB

89MB installed

● package 89MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

read

✓ from lasio import read

✗ import lasio

LASFile

✓ from lasio import LASFile

✗ import lasio

CurveItem

✓ from lasio import CurveItem

✗ import lasio

This quickstart demonstrates how to read a LAS file (simulated from a string for simplicity) using `lasio.read()`, access well header information, retrieve curve data, and convert the data into a Pandas DataFrame.

import lasio import io # Simulate a LAS file content for demonstration las_content = """~VERSION VERS. 2.00: LAS Version WRAP. NO: No line wrapping ~WELL STRT.M 10.00: START DEPTH STOP.M 20.00: STOP DEPTH STEP.M 0.50: STEP NULL. -999.25: NULL VALUE WELL. EXAMPLE WELL: WELL COMP. EXAMPLE CO: COMPANY ~CURVE DEPT.M : Depth GR.API : Gamma Ray NEUT.V/V : Neutron ~A DEPT GR NEUT 10.000 100.0 0.300 10.500 105.0 0.310 11.000 110.0 0.320 11.500 112.0 0.315 12.000 115.0 0.325 """ # Read the LAS file from a string (or from a path: lasio.read('path/to/file.las')) las_file_obj = io.StringIO(las_content) l = lasio.read(las_file_obj) # Access well information print(f"Well Name: {l.well.WELL.value}") print(f"Company: {l.well.COMP.value}") # Access curve data print(f"Gamma Ray Curve (first 3 values): {l['GR'][:3].tolist()}") print(f"Depth Curve (last 2 values): {l['DEPT'][-2:].tolist()}") # Convert to Pandas DataFrame df = l.df() print("\nDataFrame head:") print(df.head())

Debug

Known issues

gotchaLAS files frequently use non-standard encodings (e.g., 'latin-1', 'cp1252') that can cause `UnicodeDecodeError` if not specified. The default encoding for `lasio.read` is 'utf-8'.

fix

Explicitly pass the correct encoding to `lasio.read()`. Common alternatives are `encoding='latin-1'` or `encoding='cp1252'` based on the file's origin.

affects: all

breakingVersion 0.20.0 introduced a significant refactor in how curve definitions and curve data are handled, using more explicit `CurveItem` objects. Direct access patterns used in older versions might break.

fix

Review the 0.20.0 release notes. Ensure you are accessing curve metadata via `l.curves[idx].mnemonic`, `l.curves[idx].unit`, `l.curves[idx].value` and data via `l[mnemonic]` for consistency. Avoid direct mutation of `l.curves` lists if you previously did so.

affects: <0.20.0

gotchaWhen working with `lasio` data, remember to account for the `NULL` value defined in the LAS file header. `lasio` converts this value to `numpy.nan` by default.

fix

Filter or impute `numpy.nan` values in your analysis, for example: `data_clean = l['GR'][~numpy.isnan(l['GR'])]` to remove NaNs before processing.

affects: all

Upgrade

Version history

0.32latest on PyPI · released Aug 1, 2025

Audit

Dependencies

numpyrequiredCore dependency for numerical data handling.

pandasrequiredCore dependency for data frame operations and internal data structures.

Agent activity

8 hits · last 30 days

node

Resources

packagehttps://pypi.org/project/lasio/ ↗