schwifty
by example#
Basics#
IBAN
-objects are usually created from their string representation
>>> from schwifty import IBAN
>>> iban = IBAN('DE89 3704 0044 0532 0130 00')
<IBAN=DE89370400440532013000>
Afterwards you can access all relevant components and meta-information of the IBAN as attributes.
>>> str(iban)
'DE89370400440532013000'
>>> iban.formatted
'DE89 3704 0044 0532 0130 00'
>>> iban.country_code
'DE'
>>> iban.bank_code
'37040044'
>>> iban.account_code
'0532013000'
>>> len(iban)
22
For some countries it is also possible to get ahold of the BIC
associated to the bank-code
of the IBAN.
>>> iban.bic
<BIC=COBADEFFXXX>
A BIC is a unique identification code for both financial and non-financial institutes. schwifty
provides a BIC
-object, that has a similar interface to the IBAN
.
>>> from schwifty import BIC
>>> bic = BIC('PBNKDEFFXXX')
>>> bic.bank_code
'PBNK'
>>> bic.branch_code
'XXX'
>>> bic.country_code
'DE'
>>> bic.location_code
'FF'
>>> bic.domestic_bank_codes
['10010010',
'20010020',
...
'86010090']
The BIC.domestic_bank_codes
lists the country specific bank codes as you can find them as
part of the IBAN. This mapping is included in a manually curated registry that ships with schwifty
.
and currently includes entries for the following countries:
Austria
Belgium
Bulgaria
Croatia
Czech Republic
Finland
France
Germany
Great Britan
Hungary
Ireland
Latvia
Lithuania
Netherlands
Poland
Romania
Saudi Arabia
Slovakia
Slovenia
Spain
Sweden
Switzerland
Validation#
When it comes to validation the IBAN
and BIC
constructors raise an exception
whenever the provided code is incorrect for some reason. schwifty
comes with a number of
dedicated exceptions classes that help identify the concrete reason for the validation error. They
all derive from a common base exception SchwiftyException
which makes it easy to catch all
validation failures if the concrete cause is not important to you.
Note
Prior to schwifty 2021.01.0 a ValueError
was raised for all kind of validation failures. In
order to keep backwards compatiblity schwifty’s base exception is a subclass of ValueError
.
For IBANs - with respect to ISO 13616 compliance - it is checked if the account-code, the bank-code and possibly the branch-code have the correct country-specific format. E.g.:
>>> IBAN('DX89 3704 0044 0532 0130 00')
...
InvalidCountryCode: Unknown country-code DX
>>> IBAN('DE99 3704 0044 0532 0130 00')
...
InvalidChecksumDigits: Invalid checksum digits
Since version 2021.05.1 schwifty
also provides the ability to validate the country specific
checksum within the BBAN. This currently works for German and Italian banks. For German IBANs the
bank specific checksum algorithm for the account code is derived from the bank code. This
functionality is currently opt-in and can be used by providing the validate_bban paramter to the
IBAN
constructor or the IBAN.validate()
-method.
>>> iban = IBAN('DE20 2909 0900 8840 0170 00')
>>> iban.validate(validate_bban=True)
...
InvalidBBANChecksum: Invalid BBAN checksum
>>> IBAN('DE20 2909 0900 8840 0170 00', validate_bban=True)
...
InvalidBBANChecksum: Invalid BBAN checksum
For BICs it is checked if the country-code and the length is valid and if the structure matches the ISO 9362 specification.
>>> BIC('PBNKDXFFXXX')
...
InvalidCountryCode: Invalid country code DX
>>> BIC('PBNKDXFFXXXX')
...
InvalidLength: Invalid length 12
>>> BIC('PBN1DXFFXXXX')
...
InvalidStructure: Invalid structure PBN1DXFFXXXX
If catching an exception would complicate your code flow you can also use the IBAN.is_valid
property. E.g.:
if IBAN(value, allow_invalid=True).is_valid:
# do something with value
Generation#
You can generate IBAN
-objects from country-code, bank-code and account-number by using the
IBAN.generate()
-method. It will automatically calculate the correct checksum digits for
you.
>>> iban = IBAN.generate('DE', bank_code='10010010', account_code='12345')
<IBAN=DE40100100100000012345>
>>> iban.checksum_digits
'40'
Notice that even that the account-code has less digits than required (in Germany accounts should be 10 digits long), zeros have been added at the correct location.
For some countries you can also generate BIC
-objects from local
bank-codes, e.g.:
>>> bic = BIC.from_bank_code('DE', '43060967')
>>> bic.formatted
'GENO DE M1 GLS'
In case there are multiple BICs that can be related to a domestic bank code you can also use the
BIC.candidates_from_bank_code()
-method to get a list of all knwon BIC candidates.
>>> BIC.candidates_from_bank_code('FR', '30004')
[<BIC=BNPAFRPPIFN>, <BIC=BNPAFRPPPAA>, <BIC=BNPAFRPPMED>, <BIC=BNPAFRPPCRN>,
<BIC=BNPAFRPP>, <BIC=BNPAFRPPPAE>, <BIC=BNPAFRPPPBQ>, <BIC=BNPAFRPPNFE>,
<BIC=BNPAFRPPPGN>, <BIC=BNPAFRPPXXX>, <BIC=BNPAFRPPBOR>, <BIC=BNPAFRPPCRM>,
<BIC=BNPAFRPPPVD>, <BIC=BNPAFRPPPTX>, <BIC=BNPAFRPPPAC>, <BIC=BNPAFRPPPLZ>,
<BIC=BNPAFRPP039>, <BIC=BNPAFRPPENG>, <BIC=BNPAFRPPNEU>, <BIC=BNPAFRPPORE>,
<BIC=BNPAFRPPPEE>, <BIC=BNPAFRPPPXV>, <BIC=BNPAFRPPIFO>]
Pydantic integration#
The IBAN
and BIC
types can be directly used for the popular data validation
library Pydantic like so
from pydantic import BaseModel
from schwifty import IBAN
class Model(BaseModel):
iban: IBAN
model = Model(iban="DE89370400440532013000") # OK
model = Model(iban="DX89370400440532013000") # Raises ValidationError due to invalid country code