source: sasview/src/sas/sascalc/dataloader/file_reader_base_class.py @ da8bb53

ESS_GUIESS_GUI_CategroyManagerESS_GUI_PrESS_GUI_better_batchESS_GUI_corfESS_GUI_model_editorESS_GUI_py2_OLDESS_GUI_sum_editorSVCC-1SasView-664costrafo411ticket-1094-headlessticket-818ticket-976ticket885ticket885bunittest-saveloadwin64bit_conda_vm
Last change on this file since da8bb53 was da8bb53, checked in by krzywon, 12 months ago

Added a 4th data loader exception for generic readers that cannot open file.

  • Property mode set to 100644
File size: 5.7 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, DefaultReaderException
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            self.extension = extension.lower()
50            # If the file type is not allowed, return nothing
51            if self.extension in self.ext or self.allow_all:
52                # Try to load the file, but raise an error if unable to.
53                try:
54                    self.load_unit_converter()
55                    self.f_open = open(filepath, 'rb')
56                    self.get_file_contents()
57                    self.sort_one_d_data()
58                except FileContentsException as e:
59                    self.handle_error_message(e.message)
60                except OSError as e:
61                    # If the file cannot be opened
62                    msg = "Unable to open file: {}\n".format(filepath)
63                    msg += e.message
64                    self.handle_error_message(msg)
65                finally:
66                    # Close the file handle if it is open
67                    if not self.f_open.closed:
68                        self.f_open.close()
69        else:
70            msg = "Unable to find file at: {}\n".format(filepath)
71            msg += "Please check your file path and try again."
72            self.handle_error_message(msg)
73        # Return a list of parsed entries that data_loader can manage
74        return self.output
75
76    def handle_error_message(self, msg):
77        """
78        Generic error handler to add an error to the current datainfo to
79        propogate the error up the error chain.
80        :param msg: Error message
81        """
82        if isinstance(self.current_datainfo, DataInfo):
83            self.current_datainfo.errors.append(msg)
84        else:
85            logger.warning(msg)
86
87    def send_to_output(self):
88        """
89        Helper that automatically combines the info and set and then appends it
90        to output
91        """
92        data_obj = combine_data_info_with_plottable(self.current_dataset,
93                                                    self.current_datainfo)
94        self.output.append(data_obj)
95
96    def load_unit_converter(self):
97        """
98        Generic unit conversion import
99        """
100        # Check whether we have a converter available
101        self.has_converter = True
102        try:
103            from sas.sascalc.data_util.nxsunit import Converter
104        except:
105            self.has_converter = False
106
107    def sort_one_d_data(self):
108        """
109        Sort 1D data along the X axis for consistency
110        """
111        final_list = []
112        for data in self.output:
113            if isinstance(data, Data1D):
114                ind = np.lexsort((data.y, data.x))
115                data.x = np.asarray([data.x[i] for i in ind])
116                data.y = np.asarray([data.y[i] for i in ind])
117                if data.dx is not None:
118                    data.dx = np.asarray([data.dx[i] for i in ind])
119                if data.dxl is not None:
120                    data.dxl = np.asarray([data.dxl[i] for i in ind])
121                if data.dxw is not None:
122                    data.dxw = np.asarray([data.dxw[i] for i in ind])
123                if data.dy is not None:
124                    data.dy = np.asarray([data.dy[i] for i in ind])
125                if data.lam is not None:
126                    data.lam = np.asarray([data.lam[i] for i in ind])
127                if data.dlam is not None:
128                    data.dlam = np.asarray([data.dlam[i] for i in ind])
129            final_list.append(data)
130        self.output = final_list
131
132    def set_all_to_none(self):
133        """
134        Set all mutable values to None for error handling purposes
135        """
136        self.current_dataset = None
137        self.current_datainfo = None
138        self.output = []
139
140    @staticmethod
141    def splitline(line):
142        """
143        Splits a line into pieces based on common delimeters
144        :param line: A single line of text
145        :return: list of values
146        """
147        # Initial try for CSV (split on ,)
148        toks = line.split(',')
149        # Now try SCSV (split on ;)
150        if len(toks) < 2:
151            toks = line.split(';')
152        # Now go for whitespace
153        if len(toks) < 2:
154            toks = line.split()
155        return toks
156
157    @abstractmethod
158    def get_file_contents(self):
159        """
160        All reader classes that inherit from FileReader must implement
161        """
162        pass
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