# -*- coding: utf-8 -*-
"""
Abstract :class:`~sidpy.io.translator.Translator` base-class
Created on Tue Nov 3 15:07:16 2015
@author: Suhas Somnath
"""
from __future__ import division, print_function, absolute_import, unicode_literals
import abc
import sys
import os
from warnings import warn
from sidpy.base.string_utils import validate_single_string_arg, \
validate_list_of_strings
if sys.version_info.major == 3:
unicode = str
else:
FileNotFoundError = ValueError
[docs]
class Translator(object):
"""
Abstract class that defines the most basic functionality of a data format
translator.
A translator converts experimental data from binary / proprietary
data formats to a single standardized HDF5 data file
"""
__metaclass__ = abc.ABCMeta
def __init__(self, *args, **kwargs):
"""
Parameters
-----------
Returns
-------
Translator object
"""
warn('Consider using sidpy.Reader instead of sidpy.Translator if '
'possible and contribute your reader to ScopeReaders',
FutureWarning)
pass
[docs]
@abc.abstractmethod
def translate(self, *args, **kwargs):
"""
Abstract method.
"""
raise NotImplementedError('The translate method needs to be '
'implemented by the child class')
[docs]
@staticmethod
def is_valid_file(file_path, *args, **kwargs):
"""
Checks whether the provided file can be read by this translator.
This basic function compares the file extension against the "extension"
keyword argument. If the extension matches, this function returns True
Parameters
----------
file_path : str
Path to raw data file
Returns
-------
file_path : str
Path to the file that needs to be provided to translate()
if the provided file was indeed a valid file
Else, None
"""
file_path = validate_single_string_arg(file_path, 'file_name')
if not os.path.exists(file_path):
raise FileNotFoundError(file_path + ' does not exist')
targ_ext = kwargs.get('extension', None)
if not targ_ext:
raise NotImplementedError('Either is_valid_file() has not been '
'implemented by this translator or the '
'"extension" keyword argument was '
'missing')
if isinstance(targ_ext, (str, unicode)):
targ_ext = [targ_ext]
targ_ext = validate_list_of_strings(targ_ext,
parm_name='(keyword argument) '
'"extension"')
# Get rid of any '.' separators that may be in the list of extensions
# Also turn to lower case for case insensitive comparisons
targ_ext = [item.replace('.', '').lower() for item in targ_ext]
file_path = os.path.abspath(file_path)
extension = os.path.splitext(file_path)[1][1:]
# Ensure extension is lower case just like targets above
extension = extension.lower()
if extension in targ_ext:
return file_path
else:
return None