import codecs
import io
import logging
import os
import re
import traceback
import numpy as np
from . import defaults
# Convoluted import for StringIO in order to support:
#
# - Python 3 - io.StringIO
# - Python 2 (optimized) - cStringIO.StringIO
# - Python 2 (all) - StringIO.StringIO
try:
import cStringIO as StringIO
except ImportError:
try: # cStringIO not available on this system
import StringIO
except ImportError: # Python 3
from io import StringIO
else:
from StringIO import StringIO
else:
from StringIO import StringIO
from . import exceptions
from .las_items import HeaderItem, CurveItem, SectionItems, OrderedDict
logger = logging.getLogger(__name__)
URL_REGEXP = re.compile(
r"^(?:http|ftp)s?://" # http:// or https://
r"(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}"
r"\.?|[A-Z0-9-]{2,}\.?)|" # (cont.) domain...
r"localhost|" # localhost...
r"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})" # ...or ip
r"(?::\d+)?" # optional port
r"(?:/?|[/?]\S+)$",
re.IGNORECASE,
)
def check_for_path_obj(file_ref):
"""Check if file_ref is a pathlib.Path object.
If file_ref is a pathlib.Path object, then return its absolute file
path as a string so it will get processed as other string filenames.
If pathlib is not available, do nothing and return file_ref.
"""
try:
from pathlib import Path
except ImportError:
return file_ref
if isinstance(file_ref, Path):
return file_ref.absolute().__str__()
else:
return file_ref
[docs]def open_file(file_ref, **encoding_kwargs):
"""Open a file if necessary.
If ``autodetect_encoding=True`` then either ``cchardet`` or ``chardet``
needs to be installed, or else an ``ImportError`` will be raised.
Arguments:
file_ref (file-like object, str): either a filename, an open file
object, or a string containing the contents of a file.
See :func:`lasio.reader.open_with_codecs` for keyword arguments that can be
used here.
Returns:
tuple of an open file-like object, and the encoding that
was used to decode it (if it were read from disk).
"""
file_ref = check_for_path_obj(file_ref)
encoding = None
if isinstance(file_ref, str): # file_ref != file-like object, so what is it?
lines = file_ref.splitlines()
first_line = lines[0]
if URL_REGEXP.match(first_line): # it's a URL
logger.info("Loading URL {}".format(first_line))
try:
import urllib2
response = urllib2.urlopen(first_line)
encoding = response.headers.getparam("charset")
tmp_str = response.read()
tmp_list = tmp_str.splitlines()
new_str = "\n".join(tmp_list)
# file_ref = StringIO(response.read())
file_ref = StringIO(new_str)
logger.debug("Retrieved data had encoding {}".format(encoding))
except ImportError:
import urllib.request
response = urllib.request.urlopen(file_ref)
if response.headers.get_content_charset() is None:
if "encoding" in encoding_kwargs:
encoding = encoding_kwargs["encoding"]
else:
encoding = "utf-8"
else:
encoding = response.headers.get_content_charset()
# newline=None causes StringIO to use universal-newline:
# Lines in the input can end in '\n', '\r', or '\r\n', and these are
# translated into '\n' before being returned to the caller.
file_ref = StringIO(response.read().decode(encoding), newline=None)
logger.debug("Retrieved data decoded via {}".format(encoding))
elif len(lines) > 1: # it's LAS data as a string.
file_ref = StringIO(file_ref)
else: # it must be a filename
file_ref, encoding = open_with_codecs(first_line, **encoding_kwargs)
return file_ref, encoding
[docs]def open_with_codecs(
filename,
encoding=None,
encoding_errors="replace",
autodetect_encoding=True,
autodetect_encoding_chars=4000,
):
"""
Read Unicode data from file.
Arguments:
filename (str): path to file
Keyword Arguments:
encoding (str): character encoding to open file_ref with, using
:func:`io.open`.
encoding_errors (str): 'strict', 'replace' (default), 'ignore' - how to
handle errors with encodings (see
`this section
<https://docs.python.org/3/library/codecs.html#codec-base-classes>`__
of the standard library's :mod:`codecs` module for more information)
autodetect_encoding (str or bool): default True to use
`chardet <https://github.com/chardet/chardet>`__/`cchardet
<https://github.com/PyYoshi/cChardet>`__ to detect encoding.
Note if set to False several common encodings will be tried but
chardet won't be used.
autodetect_encoding_chars (int/None): number of chars to read from LAS
file for auto-detection of encoding.
Returns:
a unicode or string object
This function is called by :func:`lasio.reader.open_file`.
"""
if autodetect_encoding_chars:
nbytes = int(autodetect_encoding_chars)
else:
nbytes = None
# Forget [c]chardet - if we can locate the BOM we just assume that's correct.
nbytes_test = min(32, os.path.getsize(filename))
with open(filename, mode="rb") as test:
raw = test.read(nbytes_test)
if raw.startswith(codecs.BOM_UTF8):
encoding = "utf-8-sig"
autodetect_encoding = False
# If BOM wasn't found...
if (autodetect_encoding) and (not encoding):
with open(filename, mode="rb") as test:
if nbytes is None:
raw = test.read()
else:
raw = test.read(nbytes)
encoding = get_encoding(autodetect_encoding, raw)
autodetect_encoding = False
# Or if no BOM found & chardet not installed
if (not autodetect_encoding) and (not encoding):
encoding = adhoc_test_encoding(filename)
if encoding:
logger.info(
"{} was found by ad hoc to work but note it might not"
" be the correct encoding".format(encoding)
)
# Now open and return the file-like object
logger.info(
'Opening {} as {} and treating errors with "{}"'.format(
filename, encoding, encoding_errors
)
)
file_obj = io.open(filename, mode="r", encoding=encoding, errors=encoding_errors)
return file_obj, encoding
def adhoc_test_encoding(filename):
test_encodings = ["ascii", "windows-1252", "latin-1"]
for i in test_encodings:
encoding = i
with io.open(filename, mode="r", encoding=encoding) as f:
try:
f.readline()
break
except UnicodeDecodeError:
logger.debug("{} tested, raised UnicodeDecodeError".format(i))
pass
encoding = None
return encoding
[docs]def get_encoding(auto, raw):
"""
Automatically detect character encoding.
Arguments:
auto (str): auto-detection of character encoding - can be either
'chardet', 'cchardet', False, or True (the latter will pick the
fastest available option)
raw (bytes): array of bytes to detect from
Returns:
A string specifying the character encoding.
"""
if auto is True:
try:
import cchardet as chardet
except ImportError:
try:
import chardet
except ImportError:
logger.debug(
"chardet or cchardet is recommended for automatic"
" detection of character encodings. Instead trying some"
" common encodings."
)
return None
else:
logger.debug("get_encoding Using chardet")
method = "chardet"
else:
logger.debug("get_encoding Using cchardet")
method = "cchardet"
elif auto.lower() == "chardet":
import chardet
logger.debug("get_encoding Using chardet")
method = "chardet"
elif auto.lower() == "cchardet":
import cchardet as chardet
logger.debug("get_encoding Using cchardet")
method = "cchardet"
result = chardet.detect(raw)
logger.debug(
"{} method detected encoding of {} at confidence {}".format(
method, result["encoding"], result["confidence"]
)
)
return result["encoding"]
def find_sections_in_file(file_obj):
"""Find LAS sections in a file.
Returns: a list of lists *(k, first_line_no, last_line_no, line]*.
*file_pos* is the position in the *file_obj* in bytes,
*first_line_no* is the first line number of the section (starting
from zero), and *line* is the contents of the section title/definition
i.e. beginning with ``~`` but stripped of beginning or ending whitespace
or line breaks.
"""
file_pos = int(file_obj.tell())
starts = []
ends = []
line_no = 0
line = file_obj.readline()
# for i, line in enumerate(file_obj):
while line:
sline = line.strip().strip("\n")
if sline.startswith("~"):
starts.append((file_pos, line_no, sline))
if len(starts) > 1:
ends.append(line_no - 1)
file_pos = int(file_obj.tell())
line = file_obj.readline()
line_no = line_no + 1
ends.append(line_no)
section_positions = []
for j, (file_pos, first_line_no, sline) in enumerate(starts):
section_positions.append((file_pos, first_line_no, ends[j], sline))
return section_positions
def determine_section_type(section_title):
"""Return the type of the LAS section based on its title
>>> determine_section_type("~Curves Section")
"Header"
>>> determine_section_type("~ASCII")
"Data"
Returns: bool
"""
stitle = section_title.strip().strip("\n")
if stitle[:2] == "~A":
return "Data"
elif stitle[:2] == "~O":
return "Header (other)"
# This is las3 transitional code till data parsing is robust for ~A and
# '_Data' sections
elif re.search("_Data", stitle):
return "Las3_Data"
else:
return "Header items"
[docs]def read_file_contents(
file_obj, regexp_subs, value_null_subs, ignore_data=False, remove_line_filter="#"
):
"""Read file contents into memory.
Arguments:
file_obj (open file-like object)
Keyword Arguments:
null_subs (bool): True will substitute ``numpy.nan`` for invalid values
ignore_data (bool): if True, do not read in the numerical data in the
~ASCII section
remove_line_filter (str, func): string or function for removing/ignoring lines
in the data section e.g. a function which accepts a string (a line from the
data section) and returns either True (do not parse the line) or False
(parse the line). If this argument is a string it will instead be converted
to a function which rejects all lines starting with that value e.g. ``"#"``
will be converted to ``lambda line: line.strip().startswith("#")``
Returns:
OrderedDict
I think of the returned dictionary as a "raw section". The keys are
the first line of the LAS section, including the tilde. Each value is
a dict with either::
{"section_type": "header",
"title": str, # title of section (including the ~)
"lines": [str, ], # a list of the lines from the lAS file
"line_nos": [int, ] # line nos from the original file
}
or::
{"section_type": "data",
"title": str, # title of section (including the ~)
"start_line": int, # location of data section (the title line)
"ncols": int, # no. of columns on first line of data,
"array": ndarray # 1-D numpy.ndarray,
}
"""
sections = OrderedDict()
sect_lines = []
sect_line_nos = []
sect_title_line = None
section_exists = False
for i, line in enumerate(file_obj):
logger.debug("Reading line {i}: {line}".format(i=i, line=line.strip("\n")))
line = line.strip()
if not line:
continue
if line.upper().startswith("~A"):
logger.debug(
"Line {i}: start of data section {line}".format(
i=i, line=line.strip("\n")
)
)
# HARD CODED FOR VERSION 1.2 and 2.0; needs review for 3.0
# We have finished looking at the metadata and need
# to start reading numerical data.
if not sect_title_line is None:
sections[sect_title_line] = {
"section_type": "header",
"title": sect_title_line,
"lines": sect_lines,
"line_nos": sect_line_nos,
}
sect_lines = []
sect_line_nos = []
if not ignore_data:
try:
data = read_data_section_iterative(
file_obj,
regexp_subs,
value_null_subs,
remove_line_filter=remove_line_filter,
)
except KeyboardInterrupt:
raise
except:
raise exceptions.LASDataError(
traceback.format_exc()[:-1]
+ " in data section beginning line {}".format(i + 1)
)
sections[line] = {
"section_type": "data",
"start_line": i,
"title": line,
"array": data,
}
logger.debug('Data section ["array"].shape = {}'.format(data.shape))
section_exists = False
break
elif line.startswith("~"):
logger.debug(
"Line {i}: start of header section {line}".format(
i=i, line=line.strip("\n")
)
)
if section_exists:
# We have ended a section and need to start the next
if not sect_title_line is None:
sections[sect_title_line] = {
"section_type": "header",
"title": sect_title_line,
"lines": sect_lines,
"line_nos": sect_line_nos,
}
sect_lines = []
sect_line_nos = []
else:
# We are entering into a section for the first time
section_exists = True
pass
sect_title_line = line # either way... this is the case.
else:
# We are in the middle of a section.
if not line.startswith("#"): # ignore commented-out lines.. for now.
sect_lines.append(line)
sect_line_nos.append(i + 1)
# If the file had header data only, and is truncated before the ~A section
# we need to save the last header section.
if section_exists and not sect_title_line is None:
sections[sect_title_line] = {
"section_type": "header",
"title": sect_title_line,
"lines": sect_lines,
"line_nos": sect_line_nos,
}
# Find the number of columns in the data section(s). This is only
# useful if WRAP = NO, but we do it for all since we don't yet know
# what the wrap setting is.
for section in sections.values():
if section["section_type"] == "data":
section["ncols"] = None
file_obj.seek(0)
for i, line in enumerate(file_obj):
if i == section["start_line"] + 1:
for pattern, sub_str in regexp_subs:
line = re.sub(pattern, sub_str, line)
section["ncols"] = len(line.split())
break
return sections
def convert_remove_line_filter(filt):
"""Ensure that the line filter is a function.
Arguments:
filt (str, func): string or function for removing/ignoring lines
in the data section e.g. a function which accepts a string (a line from the
data section) and returns either True (do not parse the line) or False
(parse the line). If this argument is a string it will instead be converted
to a function which rejects all lines starting with that value e.g. ``"#"``
will be converted to ``lambda line: line.strip().startswith("#")``
Returns: function which takes a string (a data section line) and returns True
or False.
"""
if isinstance(filt, str):
value = str(filt)
filt = lambda line: line.strip().startswith(value)
return filt
def inspect_data_section(file_obj, line_nos, regexp_subs, remove_line_filter="#"):
"""Determine how many columns there are in the data section.
Arguments:
file_obj: file-like object open for reading at the beginning of the section
line_nos (tuple): the first and last line no of the section to read
regexp_subs (list): each item should be a tuple of the pattern and
substitution string for a call to re.sub() on each line of the
data section. See defaults.py READ_SUBS and NULL_SUBS for examples.
remove_line_filter (str, func): string or function for removing/ignoring lines
in the data section e.g. a function which accepts a string (a line from the
data section) and returns either True (do not parse the line) or False
(parse the line). If this argument is a string it will instead be converted
to a function which rejects all lines starting with that value e.g. ``"#"``
will be converted to ``lambda line: line.strip().startswith("#")``
Returns: integer number of columns or -1 where they are different.
"""
remove_line_filter = convert_remove_line_filter(remove_line_filter)
line_no = line_nos[0]
title_line = file_obj.readline()
item_counts = []
for i, line in enumerate(file_obj):
line_no = line_no + 1
line = line.strip("\n").strip()
if remove_line_filter(line):
continue
else:
for pattern, sub_str in regexp_subs:
line = re.sub(pattern, sub_str, line)
n_items = len(line.split())
logger.debug(
"Line {}: {} items counted in '{}'".format(line_no + 1, n_items, line)
)
item_counts.append(n_items)
if (line_no == line_nos[1]) or (i >= 20):
break
try:
assert len(set(item_counts)) == 1
except AssertionError:
return -1
else:
return item_counts[0]
[docs]def read_data_section_iterative(
file_obj, line_nos, regexp_subs, value_null_subs, remove_line_filter
):
"""Read data section into memory.
Arguments:
file_obj: file-like object open for reading at the beginning of the section
line_nos (tuple): the first and last line no of the section to read
regexp_subs (list): each item should be a tuple of the pattern and
substitution string for a call to re.sub() on each line of the
data section. See defaults.py READ_SUBS and NULL_SUBS for examples.
value_null_subs (list): list of numerical values to be replaced by
numpy.nan values.
remove_line_filter (str or func): string or function for removing/ignoring lines
in the data section e.g. a function which accepts a string (a line from the
data section) and returns either True (do not parse the line) or False
(parse the line). If this argument is a string it will instead be converted
to a function which rejects all lines starting with that value e.g. ``"#"``
will be converted to ``lambda line: line.strip().startswith("#")``
Returns:
A 1-D numpy ndarray.
"""
remove_line_filter = convert_remove_line_filter(remove_line_filter)
title = file_obj.readline()
def items(f, start_line_no, end_line_no):
line_no = start_line_no
for line in f:
line_no += 1
logger.debug(
"Line {}: reading data '{}'".format(
line_no + 1, line.strip("\n").strip()
)
)
if remove_line_filter(line):
continue
else:
for pattern, sub_str in regexp_subs:
line = re.sub(pattern, sub_str, line)
line = line.replace(chr(26), "")
for item in line.split():
try:
yield np.float64(item)
except ValueError:
yield item
if line_no == end_line_no:
break
array = np.array(
[i for i in items(file_obj, start_line_no=line_nos[0], end_line_no=line_nos[1])]
)
for value in value_null_subs:
array[array == value] = np.nan
return array
[docs]def get_substitutions(read_policy, null_policy):
"""Parse read and null policy definitions into a list of regexp and value
substitutions.
Arguments:
read_policy (str, list, or substitution): either (1) a string defined in
defaults.READ_POLICIES; (2) a list of substitutions as defined by
the keys of defaults.READ_SUBS; or (3) a list of actual substitutions
similar to the values of defaults.READ_SUBS. You can mix (2) and (3)
together if you want.
null_policy (str, list, or sub): as for read_policy but for
defaults.NULL_POLICIES and defaults.NULL_SUBS
Returns:
regexp_subs, value_null_subs, version_NULL - two lists and a bool.
The first list is pairs of regexp patterns and substrs, and the second
list is just a list of floats or integers. The bool is whether or not
'NULL' was located as a substitution.
"""
regexp_subs = []
numerical_subs = []
version_NULL = False
for policy_typ, policy, policy_subs, subs in (
("read", read_policy, defaults.READ_POLICIES, defaults.READ_SUBS),
("null", null_policy, defaults.NULL_POLICIES, defaults.NULL_SUBS),
):
try:
is_policy = policy in policy_subs
except TypeError:
is_policy = False
if is_policy:
logger.debug('using {} policy of "{}"'.format(policy_typ, policy))
all_subs = []
for sub in policy_subs[policy]:
logger.debug("adding substitution {}".format(sub))
if sub in subs:
all_subs += subs[sub]
if sub == "NULL":
logger.debug("located substition for LAS.version.NULL as True")
version_NULL = True
else:
all_subs = []
for item in policy:
if item in subs:
all_subs += subs[item]
if item == "NULL":
logger.debug(
"located substitution for LAS.version.NULL as True"
)
version_NULL = True
else:
all_subs.append(item)
for item in all_subs:
try:
iter(item)
except TypeError:
logger.debug("added numerical substitution: {}".format(item))
numerical_subs.append(item)
else:
logger.debug(
'added regexp substitution: pattern={} substr="{}"'.format(
item[0], item[1]
)
)
regexp_subs.append(item)
numerical_subs = [n for n in numerical_subs if not n is None]
return regexp_subs, numerical_subs, version_NULL
def parse_header_items_section(
file_obj,
line_nos,
version,
ignore_header_errors=False,
mnemonic_case="preserve",
ignore_comments=("#",),
):
"""Parse a header section dict into a SectionItems containing HeaderItems.
Arguments:
file_obj: file-like object open for reading at the beginning of the section
line_nos (tuple): the first and last line no of the section to read
version (float): either 1.2 or 2.0
Keyword Arguments:
ignore_header_errors (bool): if True, issue HeaderItem parse errors
as :func:`logging.warning` calls instead of a
:exc:`lasio.exceptions.LASHeaderError` exception.
mnemonic_case (str): 'preserve': keep the case of HeaderItem mnemonics
'upper': convert all HeaderItem mnemonics to uppercase
'lower': convert all HeaderItem mnemonics to lowercase
ignore_comments (False, True, or list): ignore lines starting with these
characters; by default True as '#'.
Returns:
:class:`lasio.SectionItems`
"""
line_no = line_nos[0]
title = file_obj.readline()
title = title.strip("\n").strip()
logger.debug("Line {}: Section title parsed as '{}'".format(line_no + 1, title))
parser = SectionParser(title, version=version)
section = SectionItems()
assert mnemonic_case in ("upper", "lower", "preserve")
if not mnemonic_case == "preserve":
section.mnemonic_transforms = True
for i, line in enumerate(file_obj):
line_no = line_no + 1
line = line.strip("\n").strip()
if not line:
logger.debug("Line {}: empty, ignoring".format(line_no + 1))
elif line[0] in ignore_comments:
logger.debug(
"Line {}: treating as a comment and ignoring: '{}'".format(
line_no + 1, line
)
)
else:
# We have arrived at a new section so break and return the previous
# section's object.
if line.startswith("~"):
break
try:
values = read_line(line, section_name=parser.section_name2)
except:
message = 'Line {} (section {}): "{}"'.format(line_no + 1, title, line)
if ignore_header_errors:
logger.warning(message)
else:
raise exceptions.LASHeaderError(message)
else:
if mnemonic_case == "upper":
values["name"] = values["name"].upper()
elif mnemonic_case == "lower":
values["name"] = values["name"].lower()
item = parser(**values)
logger.debug("Line {}: parsed as {}".format(line_no + 1, item))
section.append(item)
if line_no == line_nos[1]:
break
return section
[docs]class SectionParser(object):
"""Parse lines from header sections.
Arguments:
title (str): title line of section. Used to understand different
order formatting across the special sections ~C, ~P, ~W, and ~V,
depending on version 1.2 or 2.0.
Keyword Arguments:
version (float): version to parse according to. Default is 1.2.
"""
def __init__(self, title, version=1.2):
las3_section_indicators = ["_DATA", "_PARAMETER", "_DEFINITION"]
is_like_las3_section = any(
[section_str in title.upper() for section_str in las3_section_indicators]
)
# On the first call to SectionParser ~Version hasn't been parsed. So
# the version number will report the default. Although the ~Version
# section is supposed to be the first section, there can be las files
# in the wild that don't have the ~Version or doesn't have it first. In
# those cases a Las3 file would end up parsed as a Las2 file or
# partially parsed as a Las2 file.
if version == 3.0 and is_like_las3_section:
self.func = self.metadata
self.section_name2 = title
self.default_order = "value:descr"
self.orders = {}
elif title.upper().startswith("~C"):
self.func = self.curves
self.section_name2 = "Curves"
elif title.upper().startswith("~P"):
self.func = self.params
self.section_name2 = "Parameter"
elif title.upper().startswith("~W"):
self.func = self.metadata
self.section_name2 = "Well"
elif title.upper().startswith("~V"):
self.func = self.metadata
self.section_name2 = "Version"
else:
logger.info("Unknown section name {}".format(title.upper()))
self.func = self.metadata
self.section_name2 = title
self.default_order = "value:descr"
self.orders = {}
self.version = version
self.section_name = title
defs = defaults.ORDER_DEFINITIONS
if self.section_name2 in defs[self.version]:
section_orders = defs[self.version][self.section_name2]
self.default_order = section_orders[0] #
self.orders = {}
for order, mnemonics in section_orders[1:]:
for mnemonic in mnemonics:
self.orders[mnemonic] = order
def __call__(self, **keys):
"""Return the correct object for this type of section.
Refer to :meth:`lasio.reader.SectionParser.metadata`,
:meth:`lasio.reader.SectionParser.params`, and
:meth:`lasio.reader.SectionParser.curves` for the methods actually
used by this routine.
Keyword arguments should be the key:value pairs returned by
:func:`lasio.reader.read_header_line`.
"""
item = self.func(**keys)
return item
def num(self, x, default=None):
"""Attempt to parse a number.
Arguments:
x (str, int, float): potential number
default (int, float, None): fall-back option
Returns:
int, float, or **default** - from most to least preferred types.
"""
if default is None:
default = x
# in case it is a string.
try:
pattern, sub = defaults.READ_SUBS["comma-decimal-mark"][0]
x = re.sub(pattern, sub, x)
except:
pass
try:
return np.int(x)
except:
try:
x = np.float(x)
except:
return default
if np.isfinite(x):
return x
else:
return default
def strip_brackets(self, x):
x = x.strip()
if len(x) >= 2:
if (x[0] == "[" and x[-1] == "]") or (x[0] == "(" and x[-1] == ")"):
return x[1:-1]
return x
def metadata(self, **keys):
"""Return HeaderItem correctly formatted according to the order
prescribed for LAS v 1.2 or 2.0 for the ~W section.
Keyword arguments should be the key:value pairs returned by
:func:`lasio.reader.read_header_line`.
"""
# number_strings: fields that shouldn't be converted to numbers
number_strings = ["API", "UWI"]
key_order = self.orders.get(keys["name"], self.default_order)
value = ""
descr = ""
if key_order == "value:descr":
value = keys["value"]
descr = keys["descr"]
elif key_order == "descr:value":
value = keys["descr"]
descr = keys["value"]
if keys["name"].upper() not in number_strings:
value = self.num(value)
item = HeaderItem(
keys["name"], # mnemonic
self.strip_brackets(keys["unit"]), # unit
value, # value
descr, # descr
)
return item
def curves(self, **keys):
"""Return CurveItem.
Keyword arguments should be the key:value pairs returned by
:func:`lasio.reader.read_header_line`.
"""
item = CurveItem(
keys["name"], # mnemonic
self.strip_brackets(keys["unit"]), # unit
keys["value"], # value
keys["descr"], # descr
)
return item
def params(self, **keys):
"""Return HeaderItem for ~P section (the same between 1.2 and 2.0 specs)
Keyword arguments should be the key:value pairs returned by
:func:`lasio.reader.read_header_line`.
"""
return HeaderItem(
keys["name"], # mnemonic
self.strip_brackets(keys["unit"]), # unit
self.num(keys["value"]), # value
keys["descr"], # descr
)
def read_line(*args, **kwargs):
"""Retained for backwards-compatibility.
See :func:`lasio.reader.read_header_line`.
"""
return read_header_line(*args, **kwargs)
def configure_metadata_patterns(line, section_name):
"""Configure regular-expression patterns to parse section meta-data lines.
Arguments:
line (str): line from LAS header section
section_name (str): Name of the section the 'line' is from.
Returns:
An array of regular-expression strings (patterns).
"""
# Default return value
patterns = []
# Default regular expressions for name, value and desc fields
name_re = r"\.?(?P<name>[^.]*)\."
value_re = r"(?P<value>.*):"
desc_re = r"(?P<descr>.*)"
# Default regular expression for unit field. Note that we
# attempt to match "1000 psi" as a special case which allows
# a single whitespace character, in contradiction to the LAS specification
# See GitHub issue #363 for details.
unit_re = r"(?P<unit>([0-9]+\s)?[^\s]*)"
# Alternate regular expressions for special cases
value_without_colon_delimiter_re = r"(?P<value>[^:]*)"
value_with_time_colon_re = (
r"(?P<value>.*?)(?:(?<!( [0-2][0-3]| hh| HH)):(?!([0-5][0-9]|mm|MM)))"
)
name_with_dots_re = r"\.?(?P<name>[^.].*[.])\."
no_desc_re = ""
# Configure special cases
# 1. missing colon delimiter and description field
# 2. double_dots '..' caused by mnemonic abbreviation (with period)
# next to the dot delimiter.
if not ":" in line:
# If there isn't a colon delimiter then there isn't
# a description field either.
value_re = value_without_colon_delimiter_re
desc_re = no_desc_re
if ".." in line and section_name == "Curves":
name_re = name_with_dots_re
else:
if ".." in line and section_name == "Curves":
double_dot = line.find("..")
desc_colon = line.rfind(":")
# Check that a double_dot is not in the
# description string.
if double_dot < desc_colon:
name_re = name_with_dots_re
if section_name == "Parameter":
# Search for a value entry with a time-value first.
pattern = name_re + unit_re + value_with_time_colon_re + desc_re
patterns.append(pattern)
# Add the regular pattern for all section_names
# for the Parameter section this will run after time-value pattern
pattern = name_re + unit_re + value_re + desc_re
patterns.append(pattern)
return patterns