source: sasview/src/sas/sascalc/dataloader/file_reader_base_class.py @ b09095a

ESS_GUIESS_GUI_CategroyManagerESS_GUI_DocsESS_GUI_PrESS_GUI_corfESS_GUI_iss957ESS_GUI_iss959ESS_GUI_maskingESS_GUI_model_editorESS_GUI_py2_OLDESS_GUI_reportingSVCC-1SasView-664costrafo411ticket-1094-headlessticket-1111ticket-818ticket-976ticket885ticket885bunittest-saveloadwin64bit_conda_vm
Last change on this file since b09095a was b09095a, checked in by krzywon, 15 months ago

Refactor ASCII reader to use FileReader? class.

  • Property mode set to 100644
File size: 5.5 KB
Line 
1"""
2This is the base file reader class most file readers should inherit from.
3All generic functionality required for a file loader/reader is built into this
4class
5"""
6
7import os
8import logging
9import numpy as np
10from abc import abstractmethod
11from loader_exceptions import NoKnownLoaderException, FileContentsException,\
12    DataReaderException
13from data_info import Data1D, Data2D, DataInfo, plottable_1D, plottable_2D,\
14    combine_data_info_with_plottable
15
16logger = logging.getLogger(__name__)
17
18
19class FileReader(object):
20    # List of Data1D and Data2D objects to be sent back to data_loader
21    output = []
22    # Current plottable_(1D/2D) object being loaded in
23    current_dataset = None
24    # Current DataInfo object being loaded in
25    current_datainfo = None
26    # String to describe the type of data this reader can load
27    type_name = "ASCII"
28    # Wildcards to display
29    type = ["Text files (*.txt|*.TXT)"]
30    # List of allowed extensions
31    ext = ['.txt']
32    # Bypass extension check and try to load anyway
33    allow_all = False
34    # Able to import the unit converter
35    has_converter = True
36    # Open file handle
37    f_open = None
38    # Default value of zero
39    _ZERO = 1e-16
40
41    def read(self, filepath):
42        """
43        Basic file reader
44       
45        :param filepath: The full or relative path to a file to be loaded
46        """
47        if os.path.isfile(filepath):
48            basename, extension = os.path.splitext(os.path.basename(filepath))
49            # If the file type is not allowed, return nothing
50            if extension in self.ext or self.allow_all:
51                # Try to load the file, but raise an error if unable to.
52                try:
53                    self.unit_converter()
54                    self.f_open = open(filepath, 'rb')
55                    self.get_file_contents()
56                    self.sort_one_d_data()
57                except RuntimeError:
58                    # Reader specific errors
59                    # TODO: Give a specific error.
60                    pass
61                except OSError as e:
62                    # If the file cannot be opened
63                    msg = "Unable to open file: {}\n".format(filepath)
64                    msg += e.message
65                    self.handle_error_message(msg)
66                except Exception as e:
67                    # Handle any other generic error
68                    # TODO: raise or log?
69                    raise
70                finally:
71                    if not self.f_open.closed:
72                        self.f_open.close()
73        else:
74            msg = "Unable to find file at: {}\n".format(filepath)
75            msg += "Please check your file path and try again."
76            self.handle_error_message(msg)
77        # Return a list of parsed entries that data_loader can manage
78        return self.output
79
80    def handle_error_message(self, msg):
81        """
82        Generic error handler to add an error to the current datainfo to
83        propogate the error up the error chain.
84        :param msg: Error message
85        """
86        if isinstance(self.current_datainfo, DataInfo):
87            self.current_datainfo.errors.append(msg)
88        else:
89            logger.warning(msg)
90
91    def send_to_output(self):
92        """
93        Helper that automatically combines the info and set and then appends it
94        to output
95        """
96        data_obj = combine_data_info_with_plottable(self.current_dataset,
97                                                    self.current_datainfo)
98        self.output.append(data_obj)
99
100    def unit_converter(self):
101        """
102        Generic unit conversion import
103        """
104        # Check whether we have a converter available
105        self.has_converter = True
106        try:
107            from sas.sascalc.data_util.nxsunit import Converter
108        except:
109            self.has_converter = False
110
111    def sort_one_d_data(self):
112        """
113        Sort 1D data along the X axis for consistency
114        """
115        final_list = []
116        for data in self.output:
117            if isinstance(data, Data1D):
118                ind = np.lexsort((data.y, data.x))
119                data.x = np.asarray([data.x[i] for i in ind])
120                data.y = np.asarray([data.y[i] for i in ind])
121                if data.dx is not None:
122                    data.dx = np.asarray([data.dx[i] for i in ind])
123                if data.dxl is not None:
124                    data.dxl = np.asarray([data.dxl[i] for i in ind])
125                if data.dxw is not None:
126                    data.dxw = np.asarray([data.dxw[i] for i in ind])
127                if data.dy is not None:
128                    data.dy = np.asarray([data.dy[i] for i in ind])
129                if data.lam is not None:
130                    data.lam = np.asarray([data.lam[i] for i in ind])
131                if data.dlam is not None:
132                    data.dlam = np.asarray([data.dlam[i] for i in ind])
133            final_list.append(data)
134        self.output = final_list
135
136    @staticmethod
137    def splitline(line):
138        """
139        Splits a line into pieces based on common delimeters
140        :param line: A single line of text
141        :return: list of values
142        """
143        # Initial try for CSV (split on ,)
144        toks = line.split(',')
145        # Now try SCSV (split on ;)
146        if len(toks) < 2:
147            toks = line.split(';')
148        # Now go for whitespace
149        if len(toks) < 2:
150            toks = line.split()
151        return toks
152
153    @abstractmethod
154    def get_file_contents(self):
155        """
156        All reader classes that inherit from FileReader must implement
157        """
158        pass
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