I used to use the following functions for saving and recalling a dictionary or list of dictionaries to a file using pickle.
- import pickle
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def import_data(file_name):
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try:
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f = open(file_name, "r")
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except IOError, e:
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# unable to open file
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Warning("Default file import error. Reverting to original defaults...")
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return None
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# file open is successful
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try:
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dd = pickle.Unpickler(f).load()
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f.close()
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# test for a dictionary or list of dictionaries
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if isinstance(dd, dict):
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return dd
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elif isinstance(dd, list):
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for i, item in enumerate(dd):
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if not isinstance(item, dict):
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Warning("**INVALID** List item %s is not a dictionary." % (i))
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return None
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# always return one dictionary
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ddr = {}
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for d in dd: ddr.update(d)
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return ddr
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else:
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# dd is not a dictionary or list of dictionaries
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Warning("Invalid imported data type.\nData must be a dictionary or list of dictionaries.")
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return None
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except:
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# file is not compatible with Unpickler - close file and warn user
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f.close()
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Warning("Invalid defaults file. Reverting to original defaults...")
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return None
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def export_data(file_name, dd):
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if check_Defaults_dir(os.path.dirname(file_name)):
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# directory exists or was created
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try:
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f = open(file_name, "w")
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pickle.Pickler(f).dump(dd)
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f.close()
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return True
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except:
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Warning("Default values file export error.")
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return False
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else:
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# directory did not exist and the user chose 'no' to create directory
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Warning("The default values file export was aborted")
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return False
