Question

I am trying to use the API in cutplace to build a custom check
http://cutplace.sourceforge.net/api.html#writing-checks

Using the included demo data and code I have tried to follow the manual, at least until it ends abruptly.

useCutplace.py:

# Validate a test CSV file.
import os.path
from cutplace import interface
from cutplace import checks
from cutplace import ranges

class FullNameLengthIsInRangeCheck(checks.AbstractCheck):
    """Check that total length of customer name is within the specified range."""
    def __init__(self, description, rule, availableFieldNames, location=None):
        super(FullNameLengthIsInRangeCheck, self).__init__(description, rule, availableFieldNames, location)
        self._fullNameRange = ranges.Range(rule)
        self.reset()
def checkRow(self, rowMap, location):
    fullName = rowMap["last_name"] + ", " + rowMap["first_name"]
    fullNameLength = len(fullName)
    try:
        self._fullNameRange.validate("full name", fullNameLength)
    except ranges.RangeValueError, error:
        raise CheckError("full name length is %d but must be in range %s: %r" \
                % (fullNameLength, self._fullNameRange, fullName))

icdPath = os.path.join("icd_customers_field_names_only.csv")
dataPath = os.path.join("customers.csv")
icd = interface.InterfaceControlDocument()
icd.read(icdPath)
for row in interface.validatedRows(icd, dataPath):
    print row

The interface control document with custom check:

,Interface: customers,
,,
,Data format,
D,Format,CSV
D,Header,1
,,
,Fields,
,Name,
F,branch_id,
F,customer_id,
F,first_name,
F,surname,
F,gender,
F,date_of_birth,

C,"full name must have at most 100 characters",FullNameLengthIsInRange,:100

customers.csv

Branch id,Customer id,First name,Surname,Gender,Date of birth
38000,16,Daisy,Mason,female,27.02.1946
38000,42,Wendy,Davis,female,30.12.1971
38000,57,Keith,Parker,male,02.06.1984
38000,76,Kenneth,Tucker,male,15.11.1908
38053,11,Carlos,Barrett,male,09.02.1929
38053,20,Terrance,Hart,male,11.03.1961
38053,34,Lori,Dunn,female,26.09.1996
38053,73,Mary,Sutton,female,09.12.1982
38053,83,Lorraine,Castro,female,15.08.1978
38111,16,Esther,Newman,female,23.03.1932
38111,79,Tyler,Rose,male,17.12.1920
38111,127,Andrew,Dixon,male,02.10.1913

The error

>python useCutplace.py 
Traceback (most recent call last):
  File "useCutplace.py", line 29, in <module>
    icd.read(icdPath)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/cutplace-0.6.7-py2.6.egg/cutplace/interface.py", line 406, in read
    self._processRow(icdRowToProcess)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/cutplace-0.6.7-py2.6.egg/cutplace/interface.py", line 363, in _processRow
    self.addCheck(icdRowToProcess[1:])
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/cutplace-0.6.7-py2.6.egg/cutplace/interface.py", line 339, in addCheck
    checkClass = self._createCheckClass(checkType)
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/cutplace-0.6.7-py2.6.egg/cutplace/interface.py", line 171, in _createCheckClass
    return self._createClass("checks", checkType, "Check", "check")
  File "/opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages/cutplace-0.6.7-py2.6.egg/cutplace/interface.py", line 162, in _createClass
    raise fields.FieldSyntaxError("cannot find %s: %s" % (typeName, str(type)), self._location)
cutplace.fields.FieldSyntaxError: icd_customers_field_names_only.csv (R16C1): cannot find check: FullNameLengthIsInRange

Answer 1

OK the trick is to:
Put the class inside a separate module, which here I call mychecks.py

from cutplace import checks
from cutplace import ranges

class FullNameLengthIsInRangeCheck(checks.AbstractCheck):
    """Check that total length of customer name is within the specified range."""
    def __init__(self, description, rule, availableFieldNames, location=None):
        super(FullNameLengthIsInRangeCheck, self).__init__(description, rule, availableFieldNames, location)
        self._fullNameRange = ranges.Range(rule)
        self.reset()
def checkRow(self, rowMap, location):
    fullName = rowMap["surname"] + ", " + rowMap["first_name"]
    fullNameLength = len(fullName)
    try:
        self._fullNameRange.validate("full name", fullNameLength)
    except ranges.RangeValueError, error:
        raise checks.CheckError("full name length is %d but must be in range %s: %r" \
                % (fullNameLength, self._fullNameRange, fullName))

Explicitly name that module in the icd:

,Interface: customers,
,,
,Data format,
D,Format,CSV
D,Header,1
,,
,Fields,
,Name,
F,branch_id,
F,customer_id,
F,first_name,
F,surname,
F,gender,
F,date_of_birth,

C,"full name must have at most 100 characters",mychecks.FullNameLengthIsInRange,:10

The module must be in the PYTHONPATH or in the immediate directory. It does not appear that you can create a package containing the module that cutplace can see.