Я создал класс с именем "Параметры". Он отлично работает, но не с Python 2. И я хочу, чтобы он работал как на Python 2, так и на 3. Проблема идентифицирована: FileNotFoundError не существует в Python 2. Но если я использую IOError, он не работает в Python 3
Изменено в версии 3.3: EnvironmentError, IOError, WindowsError, VMSError, socket.error, select.error и mmap.error объединены в OSError.
Что мне делать? (Пожалуйста, не обсуждайте мой переносимость, у меня есть причины.)
Вот код:
#!/usr/bin/python
#-*-coding:utf-8*
#option_controller.py
#Walle Cyril
#25/01/2014
import json
import os
class Options():
"""Options is a class designed to read, add and change informations in a JSON file with a dictionnary in it.
The entire object works even if the file is missing since it re-creates it.
If present it must respect the JSON format: e.g. keys must be strings and so on.
If something corrupted the file, just destroy the file or call read_file method to remake it."""
def __init__(self,directory_name="Cache",file_name="options.json",imported_default_values=None):
#json file
self.option_file_path=os.path.join(directory_name,file_name)
self.directory_name=directory_name
self.file_name=file_name
#self.parameters_json_file={'sort_keys':True, 'indent':4, 'separators':(',',':')}
#the default data
if imported_default_values is None:
DEFAULT_INDENT = 2
self.default_values={\
"translate_html_level": 1,\
"indent_size":DEFAULT_INDENT,\
"document_title":"Titre"}
else:
self.default_values=imported_default_values
def read_file(self,read_this_key_only=False):
"""returns the value for the given key or a dictionary if the key is not given.
returns None if it s impossible"""
try:
text_in_file=open(self.option_file_path,'r').read()
except FileNotFoundError:#not 2.X compatible
text_in_file=""#if the file is not there we re-make one with default values
if text_in_file=="":#same if the file is empty
self.__insert_all_default_values()
text_in_file=open(self.option_file_path,'r').read()
try:
option_dict=json.loads(text_in_file)
except ValueError:
#if the json file is broken we re-make one with default values
self.__insert_all_default_values()
text_in_file=open(self.option_file_path,'r').read()
option_dict=json.loads(text_in_file)
if read_this_key_only:
if read_this_key_only in option_dict:
return option_dict[read_this_key_only]#
else:
#if the value is not there it should be written for the next time
if read_this_key_only in self.default_values:
self.add_option_to_file(read_this_key_only,self.default_values[read_this_key_only])
return self.default_values[read_this_key_only]
else:
#impossible because there is not default value so the value isn t meant to be here
return None
else:
return option_dict
def add_option_to_file(self,key,value):#or update
"""Adds or updates an option(key and value) to the json file if the option exists in the default_values of the object."""
option_dict=self.read_file()
if key in self.default_values:
option_dict[key]=value
open(self.option_file_path,'w').write(\
json.dumps(option_dict,sort_keys=True, indent=4, separators=(',',':')))
def __insert_all_default_values(self):
"""Recreate json file with default values.
called if the document is empty or non-existing or corrupted."""
try:
open(self.option_file_path,'w').write(\
json.dumps(self.default_values,sort_keys=True, indent=4, separators=(',',':')))
except FileNotFoundError:
os.mkdir(self.directory_name)#Create the directory
if os.path.isdir(self.directory_name):#succes
self.__insert_all_default_values()
else:
print("Impossible to write in %s and file %s not found" % (os.getcwd(),self.option_file_path))
#demo
if __name__ == '__main__':
option_file_object=Options()
print(option_file_object.__doc__)
print(option_file_object.read_file())
option_file_object.add_option_to_file("","test")#this should have no effect
option_file_object.add_option_to_file("translate_html_level","0")#this should have an effect
print("value of translate_html_level:",option_file_object.read_file("translate_html_level"))
print(option_file_object.read_file())
