#!/usr/bin/env python
##############################################################################
#
# diffpy.structure by DANSE Diffraction group
# Simon J. L. Billinge
# (c) 2007 trustees of the Michigan State University.
# All rights reserved.
#
# File coded by: Pavol Juhas
#
# See AUTHORS.txt for a list of people who contributed.
# See LICENSE_DANSE.txt for license information.
#
##############################################################################
"""Parser for automatic file format detection.
This Parser does not provide the the `toLines()` method.
"""
import os
from diffpy.structure.parsers import StructureParser, parser_index
from diffpy.structure.structureerrors import StructureFormatError
[docs]
class P_auto(StructureParser):
"""Parser with automatic detection of structure format.
This parser attempts to automatically detect the format of a given
structure file and parse it accordingly. When successful, it sets
its `format` attribute to the detected structure format.
Parameters
----------
**kw : dict
Keyword arguments for the structure parser.
Attributes
----------
format : str
Detected structure format. Initially set to "auto" and updated
after successful detection of the structure format.
pkw : dict
Keyword arguments passed to the parser.
"""
def __init__(self, **kw):
StructureParser.__init__(self)
self.format = "auto"
self.pkw = kw
return
# parseLines helpers
def _getOrderedFormats(self):
"""Build a list of relevance ordered structure formats.
This only works when `self.filename` has a known extension.
"""
from diffpy.structure.parsers import inputFormats
ofmts = [fmt for fmt in inputFormats() if fmt != "auto"]
if not self.filename:
return ofmts
# filename is defined here
filebase = os.path.basename(self.filename)
from fnmatch import fnmatch
# loop over copy of ofmts
for fmt in list(ofmts):
pattern = parser_index[fmt]["file_pattern"]
if pattern in ("*.*", "*"):
continue
anymatch = [1 for p in pattern.split("|") if fnmatch(filebase, p)]
if anymatch:
ofmts.remove(fmt)
ofmts.insert(0, fmt)
return ofmts
[docs]
def parseLines(self, lines):
"""Detect format and create `Structure` instance from a list of
lines.
Set format attribute to the detected file format.
Parameters
----------
lines : list
List of lines with structure data.
Returns
-------
Structure
`Structure` object.
Raises
------
StructureFormatError
"""
return self._wrapParseMethod("parseLines", lines)
[docs]
def parse(self, s):
"""Detect format and create `Structure` instance from a string.
Set format attribute to the detected file format.
Parameters
----------
s : str
String with structure data.
Returns
-------
Structure
`Structure` object.
Raises
------
StructureFormatError
"""
return self._wrapParseMethod("parse", s)
[docs]
def parseFile(self, filename):
"""Detect format and create Structure instance from an existing
file.
Set format attribute to the detected file format.
Parameters
----------
filename : str
Path to structure file.
Returns
-------
Structure
`Structure` object.
Raises
------
StructureFormatError
If the structure format is unknown or invalid.
IOError
If the file cannot be read.
"""
self.filename = filename
return self._wrapParseMethod("parseFile", filename)
def _wrapParseMethod(self, method, *args, **kwargs):
"""A helper evaluator method that try the specified parse method
with each registered structure parser and return the first
successful result.
Structure parsers that match structure file extension are
tried first.
Parameters
----------
method : str
Name of the parse method to call.
*args : tuple
Positional arguments for the parse method.
**kwargs : dict
Keyword arguments for the parse method.
Returns
-------
Structure
`Structure` object.
Raises
------
StructureFormatError
"""
from diffpy.structure.parsers import getParser
ofmts = self._getOrderedFormats()
stru = None
# try all parsers in sequence
parsers_emsgs = []
for fmt in ofmts:
p = getParser(fmt, **self.pkw)
try:
pmethod = getattr(p, method)
stru = pmethod(*args, **kwargs)
self.format = fmt
break
except StructureFormatError as err:
parsers_emsgs.append("%s: %s" % (fmt, err))
except NotImplementedError:
pass
if stru is None:
emsg = "\n".join(
["Unknown or invalid structure format.", "Errors per each tested structure format:"]
+ parsers_emsgs
)
raise StructureFormatError(emsg)
self.__dict__.update(p.__dict__)
return stru
# End of class P_auto
# Routines -------------------------------------------------------------------
[docs]
def getParser(**kw):
"""Return a new instance of the automatic parser.
Parameters
----------
**kw : dict
Keyword arguments for the structure parser
Returns
-------
P_auto
Instance of `P_auto`.
"""
return P_auto(**kw)