List of changes

Unreleased changes (Available on GitHub)

Version 0.32 (1 August 2025)

• #602 - The check array.shape == 1 cannot distinguish between a single row and a single column.

• #601 - switch from setup.py to pyproject.toml

• #600 - Upgrade imports to supported python versions

• #596 - Remove print statement left in stack_curves method

• #581 - added version 1 to ORDER_DEFINITIONS

• #578 - Issue #513 - LAS 3 files

Version 0.31 (18 May 2023)

• Many improvements to code style and formatting, and the documentation

• #555 - Fix problem when writing with changed data (different number of depths)

• #554 / #556 - Enable DLM (delimiter) TAB

• #552 - Remove or replace cchardet with chardet

• #530 - Detect hyphens in data section and adjust regexp_subs as needed

• Fix #322 - provide a way to consistently retrieve header items which may or may not be present in the header:

  If you try ordinary item-style access, as is normal in Python, a KeyError exception will be raised if it is missing:

  >>> permit = las.well['PRMT']
  Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    File "c:\devapps\kinverarity\projects\lasio\lasio\las_items.py", line 313, in __getitem__
      raise KeyError("%s not in %s" % (key, self.keys()))
  KeyError: "PRMT not in ['STRT', 'STOP', 'STEP', 'NULL', 'COMP', 'WELL', 'FLD', 'LOC', 'PROV', 'SRVC', 'DATE', 'UWI']"
  

  A better pattern is to use the lasio.SectionItems.get() method, which allows you to specify a default value in the case of it missing:

  >>> permit = las.well.get('PRMT', 'unknown')
  >>> permit
  HeaderItem(mnemonic="PRMT", unit="", value="unknown", descr="")
  

  You can use the add=True keyword argument if you would like this header item to be added, as well as returned:

  >>> permit = las.well.get('PRMT', 'unknown', add=True)
  >>> las.well
  [HeaderItem(mnemonic="STRT", unit="M", value="0.05", descr="FIRST INDEX VALUE"),
  HeaderItem(mnemonic="STOP", unit="M", value="136.6", descr="LAST INDEX VALUE"),
  HeaderItem(mnemonic="STEP", unit="M", value="0.05", descr="STEP"),
  HeaderItem(mnemonic="NULL", unit="", value="-99999", descr="NULL VALUE"),
  HeaderItem(mnemonic="COMP", unit="", value="", descr="COMP"),
  HeaderItem(mnemonic="WELL", unit="", value="Scorpio E1", descr="WELL"),
  HeaderItem(mnemonic="FLD", unit="", value="", descr=""),
  HeaderItem(mnemonic="LOC", unit="", value="Mt Eba", descr="LOC"),
  HeaderItem(mnemonic="SRVC", unit="", value="", descr=""),
  HeaderItem(mnemonic="CTRY", unit="", value="", descr=""),
  HeaderItem(mnemonic="STAT", unit="", value="SA", descr="STAT"),
  HeaderItem(mnemonic="CNTY", unit="", value="", descr=""),
  HeaderItem(mnemonic="DATE", unit="", value="15/03/2015", descr="DATE"),
  HeaderItem(mnemonic="UWI", unit="", value="6038-187", descr="WUNT"),
  HeaderItem(mnemonic="PRMT", unit="", value="unknown", descr="")]
  

Version 0.30 (12 May 2022)

• Fixes for #446 (Implement a numpy-based reader for the data section; `#452`_) and #444 (Provide a way to benchmark speed performance of LASFile.read; `#449`_). This leads to a more than two-fold improvement in speed (e.g. from 1091 msec to 341 msec for a large sample file).

• Fixes for #439 (Data section containing non-numeric chars is parsed entirely as str) and #227 (NULL value replacing valid value in DEPT) by allowing different data types for different columns (PRs `#459`_, `#460`_, `#461`_)

• Partially fix #375 (allow writing mnemonics in ~ASCII line; PRs `#466`_, `#471`_, `#465`_)

• Partial fix for #265 (Parse comma-delimited ~ASCII sections; `#485`_)

• Fix #83 (LAS file with more curves defined in ~C section than available in ~A section; `#480`_)

• Improve visibility and access to the Code of Conduct (`#469`_)

• Fix #453 (rounding issues when writing LAS file) (`#455`_)

• Fix #268 (remove side-effects from writer) (`#447`_, `#451`_)

• Documentation updates (`#475`_, #477, `#481`_, `#501`_, `#498`_, `#500`_)

• Fix #473 (Header lines without a period are discarded unnecessarily)

• Fix #472 (Detect and raise IOError exception for LiDAR files; `#482`_)

• Fix #483 (perfomance decrease in DEBUG logging level; `#484`_)

• Fix #478 (:1 :2 should only be appended to mnemonics when using LASFile.read) with `#479`_: Add update_curve and replace_curve_item methods to LASFile

• Fix #490 (LAS 2.1 reading error; `#491`_)

• Fix #486 (Adding a citation file, and maybe a DOI; `#487`_)

• Fix #392 (ignore_comments not mentioned in documentation; `#495`_)

• Fix #332: Describe default read_policies in docstring, with `#489`_

• Fix #502 (NumPy type conversion alias deprecation; `#503`_)

• minor performance improvements (`#470`_, )

Version 0.29 (14 April 2021)

• Fix #404 (lasio changes STEP with imprecise floating-point number behaviour; `#432`_)

• Add option len_numeric_field=-1, lhs_spacer=" ", and spacer=" " to writer.py:write (see #412; PR `#418`_)

• Fix #271 (Read quoted strings in data section properly; `#423`_)

• Fix #427 (Change null_policy to handle small non-zero values; `#429`_)

• Fix #417 (Fix parsing for empty ~Other section; `#430`_)

• Fix #402 (fixes issue when unit starts with dot; `#403`_)

• Fix #395 (Update doc examples to reflect new HeaderItem repr; `#410`_)

• Fix #426 (Update urllib.request to be the preferred urllib; `#428`_)

• Add check for pushed tag version to version tests (`#396`_)

• Update GitHub Action Python CI testing (`#399`_, `#400`_)

• Improve las_items.py:HeaderItem.__repr__ truncation logic (`#397`_)

• Remove codecs import (unused) and fix typo (`#406`_)

• Exclude LAS files from GitHubs Language Stats (`#411`_)

• Re-add try-except check around call to reader.read_data_section_iterative() (`#401`_)

• Remove reader.py:read_file_contents - unused code (see `#401`_; `#393`_)

• Add test for timestring with colon in ~Well section (see #419 - PR `#420`_)

• Fix SyntaxWarning in writer.py (`#425`_)

• Add bugfix and feature request issue templates to GitHub repository

• Apply black code style to all Python files (`#438`_, `#398`_)

• Update demo notebook for using logging levels with current behaviour

• Update contributing guide (`#437`_, `#441`_)

Version 0.28 (12 September 2020)

• Major re-write of reader code working towards LAS 3.0 support (`#327`_; `#347`_, `#345`_, `#353`_, `#355`_, `#358`_, `#367`_, `#368`_, `#369`_)

• Fix #377 (writing “None” as the value instead of “”; #377)

• Fix #373 (enable GitHub Actions CI testing on MacOS, Windows, Ubuntu; `#374`_, `#387`_)

• Fix #363 (parse composite units such as “1000 lbf” correctly; `#390`_)

• Fix #319 (allow skipping comment lines in data sections; `#391`_)

• Avoid unnecessary exceptions on reading LAS 3.0 data sections (`#385`_)

• Fix broken ReadTheDocs build

Version 0.27 (4 September 2020)

• Fix #380 (install failed without git installed; `#382`_)

Version 0.26 (31 August 2020)

• This is the final version which works on Python 2.7 (#364)

• Fix #333 (header lines not parsed when colon is in description; `#335`_)

• Fix #359 (sections not found when leading whitespace in line; `#360`_, `#361`_)

• Fix #350 (bug with NULL; `#352`_)

• Fix #339 (0.1IN not recognised as index unit; `#340`_, `#349`_)

• Fix #31 (add command-line script to convert between LAS versions; `#329`_)

• Fix #75 (add Cyrillic variant for metres; `#330`_)

• Fix `#326`_ (Support header-only LAS files–don’t lose the last header section before a missing ~A section)

• Improve documentation regarding deleting items and curves (#315, `#325`_)

• Add deprecation markers (`#331`_)

• Align json.dumps and LASFile.to_json() (`#328`_)

• Fixes and updates to setup.py relating to the adoption of setuptools_scm (#312, `#317`_, `#318`_)

• Clean up and background changes related to future LAS 3.0 support: `#334`_, `#337`_, `#338`_, `#341`_, `#342`_, `#346`_, `#348`_, `#372`_

Version 0.25.1 (1 May 2020)

• Shift to setuptools_scm (`#311`_)

• Fix #321 (EOF character causes error on read)

• Fix #182 (remove side-effect LASFile.write causing LASFile.version.VERS to change)

• Fix #310 (remove LASFile.metadata which was not working)

Version 0.25 (28 March 2020)

• Add stack_curves() method to allow joining a set of curves into a 2D array (issue #284, PR `#293`_)

• Add lasio.examples module (`#296`_)

• Fix #278 (leading zeroes were being stripped from API/UWI numbers)

• Fix `#286`_ (error on trying to write a file with one row of data)

• Fix `#258`_ (do not catch Ctrl+C when reading file)

• Fix `#292`_ (improve error checking for when trying to write non-2D data)

• Fix #277 (allow pathlib objects to lasio.read)

• Fix #264 (allow periods in mnemonics to be retained in specific cases)

• Fix #201 (adjust descr parsing in ~P section to allow times in the descr, see PR `#298`_)

• Fix `#302`_ (change in str(datetime) handling)

• Fixes to JSON output (`#300`_, #303)

• Fix #304 (add column_fmt argument to LASFile.write method)

Version 0.24

• Fix #256 (parse units in brackets and add index_unit kwarg)

Version 0.23

• Fix #259 (error when encoding missing from URL response headers)

• Fix #262 (broken build due to cchardet dependency)

Version 0.22

• Fix `#252`_ (removing case sensitivity in index_unit checks)

• Fix `#249`_ (fix bug producing df without converting to floats)

• Attempt to fix Lasso classification on GitHub

Version 0.21

• Fix #236 and #237 (can now read ASCII in ~Data section)

• Fix `#239`_ (Petrel can’t read lasio output)

Version 0.20

• Fix #233 (pickling error lost Curve.data during multiprocessing)

• Fix #226 (do not issue warning on empty ~Parameter section)

• Revised default behaviour to using null_policy=’strict’ (ref. #227)

• Fix `#221`_ (depths > 10000 were being rounded by default)

• Fix `#225`_ (file handle leaked if exception during parsing)

Version 0.19

• Fix #223 (critical version/installation bug)

Version 0.18

• Fix version numbering setup

• Fix #92 (can ignore blah blah lines in ~C section)

• Fix #209 (can now add curves with LASFile[‘mnemonic’] = [1, 2, 3])

• Fix #213 (LASFile.data is now a lazily generated property, with setter)

• Fix #218 (LASFile.append_curve was not adding data=[…] properly)

• Fix #216 (LASFile now raises KeyError for missing mnemonics)

• Fix #214 (first duplicate mnemonic when added was missing the :1)

Version 0.17

• Add Appveyor continuous integration testing

• Add example notebook for how to use python logging module

• Fix #160 (add methods to LASFile for inserting curves)

• Fix #155 (implement del keyword for header items)

• Fix #142 (implement slicing for SectionItems)

• Fix #135 (UWI numbers losing their leading zeros)

• Fix #153 (fix SectionItems pprint repr in Python 3)

• Fix #81 (accept header items with missing colon)

• Fix #71 (add Docker build for lasio to DockerHub)

• Fix #210 (allow upper/lowercase standardization of mnemonics on read)

• Document recent additions (nearly up to date) (in Sphinx docs)

Version 0.16

• Add read_policy and null_policy keywords - see documentation for details

• Fix bugs around files with missing ~V ~W ~P or ~C sections (#84 #85 #78)

• Fix #17 involving files with commas as a decimal mark

• Improve LASHeaderError traceback message

• Fix bug involving files with ~A but no data lines following

• Fix bug with blank line at start of file

• Fix bug involving missing or duplicate STRT, STOP and STEP mnemonics

Version 0.15.1

• Major performance improvements with both memory and speed

• Major improvement to read parser, now using iteration

• Add LASFile.to_excel() and LASFile.to_csv() export methods

• Improve las2excelbulk.py script

• Published new and updated Sphinx documentation

• Improved character encoding handling when chardet not installed

• autodetect_encoding=True by default

• Allow reading of multiple non-standard header sections (#167, `#168`_)

• Add flexibility in reading corrupted headers (ignore_header_errors=True)

• Add ability to avoid reading in data (ignore_data=True)

• Remove excessive debugging messages

• Fix bug #164 where FEET was not recognised as FT

• Fix major globals() bug #141 affecting LASFile.add_curve

• Add command-line version script $ lasio to show version number.

Version 0.14 and 0.15 skipped due to broken PyPI upload.

Version 0.13

• Other minor bug fixes inc inability to rename mnemonics in written LAS file.

Version 0.11.2

• Fix bug with not correctly figuring out units for LASFile.write()

• Add LASFile.add_curve(CurveItem) method which automatically goes to the old method at LASFile.add_curve_raw(mnemonic=, data=, ...) if necessary, so it should be transparent to users

Version 0.11

• Reorganise code into modules

• various

Version 0.10

• Internal change to SectionItems for future LAS 3.0 support

• Added JSON encoder

• Added examples for using pandas DataFrame (.df attribute)

• LAS > Excel script refined (las2excel.py)

Version 0.9.1 (2015-11-11)

• pandas.DataFrame now as .df attribute, bugfix

Version 0.8 (2015-08-20)

• numerous bug fixes, API documentation added

Version 0.7 (2015-08-08)

• all tests passing on Python 2.6 through 3.4

Version 0.6 (2015-08-05)

• bugfixes and renamed from las_reader to lasio

Version 0.5 (2015-08-01)

• Improvements to writing LAS files

Version 0.4 (2015-07-26)

• Improved handling of character encodings, other internal improvements

Version 0.3 (2015-07-23)

• Added Python 3 support, now reads LAS 1.2 and 2.0

Version 0.2 (2015-07-08)

• Tidied code and published on PyPI