Learning Python with pain… | Bierpiloten-Blog

… nein, der Titel dieses Posts soll Python nicht schlecht machen, im Gegenteil, es ist ein nettes Wortspiel in diesem Zusammenhang ;).

Um mal ein wenig in die Programmiersprache Python, die bei Mausbrand verwendet wird, reinzukommen, habe ich mir glaube ich das trockendste Thema überhaupt ausgesucht :-D… ich muss aber zu meiner Verteidigung sagen, dass ich der Meinung bin, man kann eine Programmiersprache nur erfolgreich lernen und einsetzen, wenn man damit auch Programme schreibt, die einen konkreten Nutzen haben und mit denen man auch etwas bewirken kann.

Nun, für mein erstes Python-Programm habe ich mir ausgesucht, dass ich für den Verein eine Schnittstelle benötige, um SEPA-Lastschriften automatisiert per Datei bei der Bank einzureichen. Dies wurde in der Vergangenheit immer händisch gemacht und ist ein langweiliger, undankbarer Job.

Das kleine Skript sepa_pain.py implementiert das Nachrichtenformat SEPA-PAIN Version 008-002 des EBICS (Electronic Banking Internet Communication Standard). Ich muss dazu sagen, dass ich einen Großteil der Logik aus einer kleinen PHP-Library geklaut habe, nur ich wollte mich ja erst mal ein wenig mit Python vertraut machen.

Nun hier ist das Programm! Für Augenkrebs und sonstiges übernehme ich keine Haftung. Ich denke auch, dass ich einiges hätte eleganter machen können, das Problem ist nur, das ich mich dazu noch zu wenig mit Python auskenne um solche Tricks zu kennen.

Daher: Quick&Dirty!

# Tiny Interface for SEPA-debits using the SEPA-PAIN-008-002-specification
# by Jan Max Meyer / bierpilot
#
# based on https://github.com/michael-dev/php-sepa-lastschrift
#
# I'm sorry for the bad code but this is my first program I wrote in Python ;)

import uuid
import re
from xml.etree.ElementTree import ElementTree, Element, SubElement, Comment, tostring
import time
from datetime import date

class SEPALastschrift(object):

    # Konstruktor
    def __init__(self, datum = date.today(), msgid = str( uuid.uuid1() ).replace("-", "" )[:-5],
                    initiator = "Horst Schlemmer", creditor_name = "Schlemmer AG",
                        creditor_iban = "DE09121688720378475751", creditor_bic = "PBNKDEFF",
                            creditor_id = "DE99XXX00000312547", ccy = "EUR",
                                cdtype = "CORE" ):
        self.datum = datum
        self.msgid = msgid
        self.initiator = initiator
        self.creditor_name = creditor_name
        self.creditor_iban = creditor_iban
        self.creditor_bic = creditor_bic
        self.creditor_id = creditor_id
        self.ccy = ccy
        self.cdtype = cdtype

        self.txtypes = [ "FRST","RCUR","OOFF","FNAL" ]
        self.txs = {}
        self.sums = {}

    # Lastschrift
    def addLastschrift( self, type, iban, bic, name, mandat,
                        mandat_sig_date = date.today(), amount = 0.0, subject = "",
                            ultimate_deb = None,
                            id = str( uuid.uuid1() ).replace("-", "" ) ):
        # Type
        if not any( type in t for t in self.txtypes ):
            print( "Type", type, "is not known" )
            return False

        #Mandat
        if not re.match( "^([A-Za-z0-9]|[\+|\?|/|\-|:|\(|\)|\.|,|']){1,35}$", mandat ):
            print( "Invalid mandat" )
            return False

        #Name
        if not re.match( "^[A-Za-z0-9\+\?/\-:\(\)\.,' ]{1,70}$", name ):
            print( "Invalid name" )
            return False

        #Subject
        if not re.match( "^[A-Za-z0-9\+\?/\-:\(\)\.,' ]{0,140}$", subject ):
            print( "Invalid subject" )
            return False

        tx = {}
        tx[ "id" ] = id
        tx[ "type" ] = type
        tx[ "name" ] = name
        tx[ "iban" ] = iban
        tx[ "bic" ] = bic
        tx[ "amount" ] = amount * 100
        tx[ "mandat" ] = mandat
        tx[ "mandat_sig_date" ] = mandat_sig_date
        tx[ "subject" ] = subject
        tx[ "ultimate_deb" ] = ultimate_deb

        if not type in self.txs.keys():
            self.txs[ type ] = []

        self.txs[ type ].append( tx )

        if not type in self.sums.keys():
            self.sums[ type ] = tx[ "amount" ]
        else:
            self.sums[ type ] += tx[ "amount" ]

        return True

    def toXML( self ):
        painVersion = "008.002.02"
        painXSDFile = "pain." + painVersion + ".xsd"

        root = Element( "Document" )
        root.set( "xmlns", "urn:iso:std:iso:20022:tech:xsd:pain." + painVersion )
        root.set( "xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance" )
        root.set( "xsi:schemaLocation", "urn:iso:std:iso:20022:tech:xsd:pain." + painVersion + " " + painXSDFile )

        init = SubElement( root, "CstmrDrctDbtInitn" )

        # Header
        header = SubElement( init, "GrpHdr" )
        SubElement( header, "MsgId" ).text = self.msgid
        SubElement( header, "CreDtTm" ).text = time.strftime( '%Y-%m-%dT%H:%M:%SZ' )
        cnt = 0
        for i in self.sums.keys():
            cnt += len( self.txs[ i ] )

        SubElement( header, "NbOfTxs" ).text = str( cnt )

        sum = 0
        for i in self.sums.keys():
            sum += self.sums[ i ]

        SubElement( header, "CtrlSum" ).text = "%d.%02d" % ( sum / 100, sum % 100 )
        SubElement( SubElement( header, "InitgPty" ), "Nm" ).text = self.initiator

        # Payments
        for type in self.txtypes:
            if type in self.txs.keys():
                #print( "---", type )
                # Payment Information Header
                payment = SubElement( init, "PmtInf")
                SubElement( payment, "PmtInfId" ).text = self.msgid + "-" + type
                SubElement( payment, "PmtMtd" ).text = "DD"
                SubElement( payment, "NbOfTxs" ).text = str( len( self.txs[ type ] ) )
                SubElement( payment, "CtrlSum" ).text = "%d.%02d" % ( self.sums[ type ] / 100, self.sums[ type ] % 100 )

                info = SubElement( payment, "PmtTpInf" )

                SubElement( SubElement( info, "SvcLvl" ), "Cd" ).text = "SEPA"
                SubElement( SubElement( info, "LclInstrm" ), "Cd" ).text = self.cdtype
                SubElement( info, "SeqTp" ).text = type
                SubElement( payment, "ReqdColltnDt" ).text = time.strftime( '%Y-%m-%d' )
                SubElement( SubElement( payment, "Cdtr" ), "Nm" ).text = self.creditor_name
                SubElement( SubElement( SubElement( payment, "CdtrAcct" ), "Id" ), "IBAN" ).text = self.creditor_iban
                SubElement( SubElement( SubElement( payment, "CdtrAgt" ), "FinInstnId" ), "BIC" ).text = self.creditor_bic
                SubElement( payment, "ChrgBr" ).text = "SLEV"

                id = SubElement( SubElement( SubElement( SubElement( payment, "CdtrSchmeId" ), "Id" ), "PrvtId" ), "Othr" )
                SubElement( id, "Id" ).text = self.creditor_id
                SubElement( SubElement( id, "SchmeNm" ), "Prtry" ).text = "SEPA"

                for tx in self.txs[ type ]:
                    info = SubElement( payment, "DrctDbtTxInf" )
                    SubElement( SubElement( info, "PmtId" ), "EndToEndId" ).text = tx[ "id" ]
                    SubElement( info, "InstdAmt", Ccy = self.ccy ).text = "%d.%02d" % ( tx[ "amount" ] / 100, tx[ "amount" ] % 100 )

                    mandat = SubElement( SubElement( info, "DrctDbtTx" ), "MndtRltdInf" )
                    SubElement( mandat, "MndtId" ).text = tx[ "mandat" ]
                    SubElement( mandat, "DtOfSgntr" ).text = tx[ "mandat_sig_date" ].strftime( "%Y-%m-%d" )

                    SubElement( SubElement( SubElement( info, "DbtrAgt" ), "FinInstnId" ), "BIC" ).text = tx[ "bic" ]
                    SubElement( SubElement( info, "Dbtr" ), "Nm" ).text = tx[ "name" ]
                    SubElement( SubElement( SubElement( info, "DbtrAcct" ), "Id" ), "IBAN" ).text = tx[ "iban" ]

                    if not tx[ "ultimate_deb" ] is None:
                        SubElement( SubElement( info, "UltmtDbtr" ), "Nm" ).text = tx[ "ultimate_deb" ]

                    SubElement( SubElement( info, "RmtInf" ), "Ustrd" ).text = tx[ "subject" ]

        return ElementTree( root )

S1 = SEPALastschrift( date.today(), initiator = "Rolph Rautenmann",
    creditor_name = "Rautenmann Devices", creditor_iban = "DE74110220100221331",
        creditor_bic = "WELADED1SWT", creditor_id = "DE33XXX000111211" )

S1.addLastschrift( "FRST", "DE17440100461122133211", "PBNKDEFF", "Yussuf Testus", "123", date.today(), 100, "Mitgliedsbeitrag" )
S1.addLastschrift( "FRST", "DE64440100440021313333", "PBNKDEFF", "Bernd Stromberg", "456", date.today(), 100, "Andere sorgen" )

xml = S1.toXML()
xml.write("test.xml", encoding="utf-8")

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# Tiny Interface for SEPA-debits using the SEPA-PAIN-008-002-specification

# by Jan Max Meyer / bierpilot

# based on https://github.com/michael-dev/php-sepa-lastschrift

# I'm sorry for the bad code but this is my first program I wrote in Python ;)

import uuid

import re

from xml.etree.ElementTree import ElementTree, Element, SubElement, Comment, tostring

import time

from datetime import date

class SEPALastschrift(object):

# Konstruktor

def __init__(self, datum = date.today(), msgid = str( uuid.uuid1() ).replace("-", "" )[:-5],

initiator = "Horst Schlemmer", creditor_name = "Schlemmer AG",

creditor_iban = "DE09121688720378475751", creditor_bic = "PBNKDEFF",

creditor_id = "DE99XXX00000312547", ccy = "EUR",

cdtype = "CORE" ):

self.datum = datum

self.msgid = msgid

self.initiator = initiator

self.creditor_name = creditor_name

self.creditor_iban = creditor_iban

self.creditor_bic = creditor_bic

self.creditor_id = creditor_id

self.ccy = ccy

self.cdtype = cdtype

self.txtypes = [ "FRST","RCUR","OOFF","FNAL" ]

self.txs = {}

self.sums = {}

# Lastschrift

def addLastschrift( self, type, iban, bic, name, mandat,

mandat_sig_date = date.today(), amount = 0.0, subject = "",

ultimate_deb = None,

id = str( uuid.uuid1() ).replace("-", "" ) ):

# Type

if not any( type in t for t in self.txtypes ):

print( "Type", type, "is not known" )

return False

#Mandat

if not re.match( "^([A-Za-z0-9]|[\+|\?|/|\-|:|$|$|\.|,|']){1,35}$", mandat ):

print( "Invalid mandat" )

return False

#Name

if not re.match( "^[A-Za-z0-9\+\?/\-:\.,' ]{1,70}$", name ):

print( "Invalid name" )

return False

#Subject

if not re.match( "^[A-Za-z0-9\+\?/\-:\.,' ]{0,140}$", subject ):

print( "Invalid subject" )

return False

tx = {}

tx[ "id" ] = id

tx[ "type" ] = type

tx[ "name" ] = name

tx[ "iban" ] = iban

tx[ "bic" ] = bic

tx[ "amount" ] = amount * 100

tx[ "mandat" ] = mandat

tx[ "mandat_sig_date" ] = mandat_sig_date

tx[ "subject" ] = subject

tx[ "ultimate_deb" ] = ultimate_deb

if not type in self.txs.keys():

self.txs[ type ] = []

self.txs[ type ].append( tx )

if not type in self.sums.keys():

self.sums[ type ] = tx[ "amount" ]

else:

self.sums[ type ] += tx[ "amount" ]

return True

def toXML( self ):

painVersion = "008.002.02"

painXSDFile = "pain." + painVersion + ".xsd"

root = Element( "Document" )

root.set( "xmlns", "urn:iso:std:iso:20022:tech:xsd:pain." + painVersion )

root.set( "xmlns:xsi", "http://www.w3.org/2001/XMLSchema-instance" )

root.set( "xsi:schemaLocation", "urn:iso:std:iso:20022:tech:xsd:pain." + painVersion + " " + painXSDFile )

init = SubElement( root, "CstmrDrctDbtInitn" )

# Header

header = SubElement( init, "GrpHdr" )

SubElement( header, "MsgId" ).text = self.msgid

SubElement( header, "CreDtTm" ).text = time.strftime( '%Y-%m-%dT%H:%M:%SZ' )

cnt = 0

for i in self.sums.keys():

cnt += len( self.txs[ i ] )

SubElement( header, "NbOfTxs" ).text = str( cnt )

sum = 0

for i in self.sums.keys():

sum += self.sums[ i ]

SubElement( header, "CtrlSum" ).text = "%d.%02d" % ( sum / 100, sum % 100 )

SubElement( SubElement( header, "InitgPty" ), "Nm" ).text = self.initiator

# Payments

for type in self.txtypes:

if type in self.txs.keys():

#print( "---", type )

# Payment Information Header

payment = SubElement( init, "PmtInf")

SubElement( payment, "PmtInfId" ).text = self.msgid + "-" + type

SubElement( payment, "PmtMtd" ).text = "DD"

SubElement( payment, "NbOfTxs" ).text = str( len( self.txs[ type ] ) )

SubElement( payment, "CtrlSum" ).text = "%d.%02d" % ( self.sums[ type ] / 100, self.sums[ type ] % 100 )

info = SubElement( payment, "PmtTpInf" )

SubElement( SubElement( info, "SvcLvl" ), "Cd" ).text = "SEPA"

SubElement( SubElement( info, "LclInstrm" ), "Cd" ).text = self.cdtype

SubElement( info, "SeqTp" ).text = type

SubElement( payment, "ReqdColltnDt" ).text = time.strftime( '%Y-%m-%d' )

SubElement( SubElement( payment, "Cdtr" ), "Nm" ).text = self.creditor_name

SubElement( SubElement( SubElement( payment, "CdtrAcct" ), "Id" ), "IBAN" ).text = self.creditor_iban

SubElement( SubElement( SubElement( payment, "CdtrAgt" ), "FinInstnId" ), "BIC" ).text = self.creditor_bic

SubElement( payment, "ChrgBr" ).text = "SLEV"

id = SubElement( SubElement( SubElement( SubElement( payment, "CdtrSchmeId" ), "Id" ), "PrvtId" ), "Othr" )

SubElement( id, "Id" ).text = self.creditor_id

SubElement( SubElement( id, "SchmeNm" ), "Prtry" ).text = "SEPA"

for tx in self.txs[ type ]:

info = SubElement( payment, "DrctDbtTxInf" )

SubElement( SubElement( info, "PmtId" ), "EndToEndId" ).text = tx[ "id" ]

SubElement( info, "InstdAmt", Ccy = self.ccy ).text = "%d.%02d" % ( tx[ "amount" ] / 100, tx[ "amount" ] % 100 )

mandat = SubElement( SubElement( info, "DrctDbtTx" ), "MndtRltdInf" )

SubElement( mandat, "MndtId" ).text = tx[ "mandat" ]

SubElement( mandat, "DtOfSgntr" ).text = tx[ "mandat_sig_date" ].strftime( "%Y-%m-%d" )

SubElement( SubElement( SubElement( info, "DbtrAgt" ), "FinInstnId" ), "BIC" ).text = tx[ "bic" ]

SubElement( SubElement( info, "Dbtr" ), "Nm" ).text = tx[ "name" ]

SubElement( SubElement( SubElement( info, "DbtrAcct" ), "Id" ), "IBAN" ).text = tx[ "iban" ]

if not tx[ "ultimate_deb" ] is None:

SubElement( SubElement( info, "UltmtDbtr" ), "Nm" ).text = tx[ "ultimate_deb" ]

SubElement( SubElement( info, "RmtInf" ), "Ustrd" ).text = tx[ "subject" ]

return ElementTree( root )

S1 = SEPALastschrift( date.today(), initiator = "Rolph Rautenmann",

creditor_name = "Rautenmann Devices", creditor_iban = "DE74110220100221331",

creditor_bic = "WELADED1SWT", creditor_id = "DE33XXX000111211" )

S1.addLastschrift( "FRST", "DE17440100461122133211", "PBNKDEFF", "Yussuf Testus", "123", date.today(), 100, "Mitgliedsbeitrag" )

S1.addLastschrift( "FRST", "DE64440100440021313333", "PBNKDEFF", "Bernd Stromberg", "456", date.today(), 100, "Andere sorgen" )

xml = S1.toXML()

xml.write("test.xml", encoding="utf-8")

Das schöne: Die Dateien, die dieses Skript ausgibt, werden sogar im Online-Banking eingelesen und akzeptiert. Es scheint also weitestgehend valide zu sein.

Allerdings muss man ja schon anmerken, dass sich die Finanzbehörde mit dem namen PAIN mal wieder alle Mühe gegeben hat… es ist wirklich schmerzhaft, diese komischen XML-Tags zu entziffern wie z.B. DtOfSgntr oder DrctDbtTxInf… wunderbar! 🙁