#create csv_query.py in /Extensions and paste below code into it
def _parseFile(file):
    """ responsible for parsing the file and returning the datastructure """
    parsed={}
    columns=[] #in order of appearance
    f=open(file, 'r')
    lines=f.readlines()
    for column in lines[0].split(','):
        column=column.strip()
        columns.append(column)
        parsed[column]=()
    
    for line in lines[1:]:
        data=line.strip().split(',')
        for x in range(0, len(columns)):
            column_name=columns[x]            
            values=parsed[column_name]           
            parsed[column_name]=values+(data[x], )

    f.close()
    return parsed    
    
def _queryCSVMapping(map, field, value):
    """ return the position (of the sequence of dat) inside the value of the mapping """
    values=map[field]
    results=() # line numbers where found
    for x in range(0, len(values)):
        if value==values[x]:
            results=results+(x,)
    return results

def _getDataFromLineNumbers(file, line_nums):
    data=() #sequence of text found
    f=open(file, 'r')
    contents=f.readlines()
    for line_num in line_nums:
        data=data+(contents[line_num+1],)
    f.close()
    return data

def csv_query(file, field, value):
    csv_mapping=_parseFile(file)
    line_number=_queryCSVMapping(csv_mapping, field, value)
    lines=_getDataFromLineNumbers(file, line_number)
    return lines #this is sequence of raw lines found


#in ZOPE create a External Method
#id: queryCSVFile
#module: csv_query
#function: csv_query

#create a datafile, lets say data.csv in /Extensions
John Smith,111-1111,123456789
John Smith,222-2222,123456789
Betty Lee,333-3333,234567890
Joe Anderson,444-4444,345678901

#now in your Script(Python)
f='e:\\zope25b1\\extensions\\data.csv' #path to file
data=context.queryCSVFile(f, 'phone', '222-2222')
return data

#and you should be returned
John Smith,222-2222,123456789

#you could in your DTMLMethod call it by
<dtml-in "queryCSVFile('e:\\zope25b1\\extensions\\data.csv', 'name', 'John Smith')">
  <dtml-var sequence-item> <br />
</dtml-in>

#and you should get
John Smith,111-1111,123456789 <br/>
John Smith,222-2222,123456789 <br/>