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https://github.com/bspeice/Melodia
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49 lines
1.2 KiB
Python
49 lines
1.2 KiB
Python
from django.db import models
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import re, itertools
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class IntegerListField(models.TextField):
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"""Store a list of integers in a database string.
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Format is:
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[<int_1>, <int_2>, <int_3>, ... , <int_n>]"""
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description = "Field type for storing lists of integers."
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__metaclass__ = models.SubfieldBase
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def __init__(self, *args, **kwargs):
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super(IntegerListField, self).__init__(*args, **kwargs)
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#Convert database to python
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def to_python(self, value):
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if isinstance(value, list):
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return value
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#Process a database string
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#Validation first
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if value[0] != '[' or value[-1] != ']':
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raise ValidationError("Invalid input to parse a list of integers!")
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#Note that any non-digit string is a valid separator
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_csv_regex = "[0-9]"
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csv_regex = re.compile(_csv_regex)
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#Synonymous to:
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#string_list = filter(None, csv_regex.findall(value))
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string_list = itertools.ifilter(None, csv_regex.findall(value))
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value_list = [int(i) for i in string_list]
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return value_list
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#Convert python to database
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def get_prep_value(self, value):
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if not isinstance(value, list):
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raise ValidationError("Invalid list given to put in database!")
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separator_string = ", "
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list_elements = separator_string.join(value)
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return "[" + list_elements + "]"
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