django-copybook

This app allows you to convert objects into fixed width records.

In version 0.1.0 we introduce an entirely new (albeit similar) interface that breaks all dependency on Django and removes the necessity of manually setting the order of fields. We call it 'fixedwidth'.

Usage:

from djcopybook.fixedwidth import Record from djcopybook.fixedwidth import fields

class Person(Record): first_name = fields.StringField(length=20) last_name = fields.StringField(length=30) siblings = fields.IntegerField(length=2) birth_date = fields.DateField(length=10, format="%Y-%m-%d")

p = Person(first_name="Joe", last_name="Smith", siblings=3, birth_date="1982-09-11") p.birth_date datetime.date(1982, 9, 11) p.to_record() 'Joe Smith 031982-09-11'

You can also set attributes after a record has been instantiated, give fields default values, and other fun stuff.

When you have a record instance, the data values will always be their python value, and when you do a to_record on the Record as a whole or an individual field it will have the fixedwidth format.

New in version 0.1.1: ListField: lets you have one field whose values are made of another complete record. Similar to COBOL's OCCURS functionality. Declaring length on the ListField tells how many times that record repeats.

USAGE: class PhoneNumber(Record): identifier = fields.StringField(length=10, default="Mobile") area_code = fields.IntegerField(length=3) prefix = fields.IntegerField(length=3) line_number = fields.IntegerField(length=4)

class Person(Record):
    first_name = fields.StringField(length=20)
    last_name = fields.StringField(length=30)
    siblings = fields.IntegerField(length=2)
    birth_date = fields.DateField(length=10, format="%Y-%m-%d")
    phone_numbers = fields.ListField(record=PhoneNumber, length=3)

>>> phone_one = PhoneNumber(area_code=515, prefix=555, line_number=2222)
>>> person = Person(first_name="Joe", last_name="Smith", siblings=3,
               birth_date="1982-09-11", phone_numbers=[phone_one])

>>> person.to_record()
'Joe                 Smith                         031982-09-11Mobile    [phone]Mobile    [phone]Mobile    [phone]'

New in version 0.1.2: Convert records from a fixed width format back into record objects

USAGE: class Person(Record): first_name = fields.StringField(length=20) last_name = fields.StringField(length=30) siblings = fields.IntegerField(length=2) birth_date = fields.DateField(length=10, format="%Y-%m-%d")

>>> fixedwidth_record = 'Joe                 Smith                         031982-09-11'
>>> person = Person.from_record(fixedwidth_record)
>>> person.first_name
'Joe'
>>> person.last_name
'Smith'
>>> person.siblings
3
>>> person.birth_date
datetime.date(1982, 9, 11)

New in version 0.1.6: FragmentField: Similar to the ListField, but only occurring one time. Useful if you have a common element included in multiple Records.

USAGE: class Phone(Record): area_code = fields.IntegerField(length=3) prefix = fields.IntegerField(length=3) line_number = fields.IntegerField(length=4)

class Contact(Record):
    name = fields.StringField(length=30)
    phone_number = fields.FragmentField(record=Phone)
    email = fields.StringField(length=30)

>>> phone = PhoneNumber(area_code=515, prefix=555, line_number=2222)
>>> contact = Contact(name="Joe", phone_number=phone, email="[e-mail]")
>>> contact.to_record()
'Joe                 [e-mail]               '


or:

>>> contact = Contact(name="Joe", email="[e-mail]")
>>> contact.phone_number.area_code = 515
>>> contact.phone_number.prefix = 555
>>> contact.phone_number.line_number = 2222
>>> contact.to_record()
'Joe                 [e-mail]               '

New in version 0.1.7: You can now populate a record object with a dictionary containing more items than the record has fields. The record will use the values if it has the associated fields, but will ignore extra data.

This is useful when populating records from a form's cleaned_data for instance if the form has more data than that specific record wants.

New in version 0.1.9:

Record now has an auto_truncate attribute you can set to truncate each field down to the expected size instead of raising an error.

USAGE:

class Sample(Record):
    field = fields.StringField(length=5)

>>> s = Sample(field='this is too long')
>>> str(s)
'this '

Notes: Because we are using OrderedDict, the new fixedwidth implementation will only work on Python 2.7 and above. (you can copy the OrderdDict class yourself if you need < 2.7)

The previous Django model implementation is pending deprecation.