http://ix.io/oDq

import csv
import os
import sys


question_list = set() # using a set to have a unique list of questions
working_dir = os.getcwd()

def find_files():
    file_list = []
    for file in os.listdir(working_dir):
        if file.endswith(".csv"):
            file_list.append(os.path.join(working_dir, file))
    return file_list

def strip_whitspaces_in_list(l):
    return [x.strip() for x in l]


def create_dict(csvfile):
    with open(csvfile) as csvdata:
        data = csv.reader(csvdata, delimiter=';')
        header = next(data)
        questions = header[1:]
        questions = strip_whitspaces_in_list(questions) #remove the silly whitespaces
        question_list.update(questions) # update the questions to the set
        for answers in data:
            user = answers[0].strip()
            answers = answers[1:]
            answers = strip_whitspaces_in_list(answers)
            questions_answer_dict = dict(zip(questions, answers))
            yield {user: questions_answer_dict}

def make_list():
    ret = []
    for csvfile in find_files():
        for data in create_dict(csvfile):
            ret.append(data)
    return ret

def generate_header():
    return ['User'] + list(question_list)

def gen_2d_list():
    data = make_list() #order is here importand, first get data to create question_list
    header = generate_header()
    ret = []
    for dataset in data:
        row = []
        for user, qa in dataset.items():
            row.append(user)
            for question in question_list:
                answer = qa.get(question, None)
                row.append(answer)
        ret.append(row)
    return [header] + ret

def writecsv(output='test.csv'):
    data = gen_2d_list()
    with open(output, 'w') as fd:
        writer = csv.writer(fd, delimiter=';')
        writer.writerows(data)

def main():
    try:
        writecsv()
    except:
        return -1
    return 0

if __name__ == '__main__':
    sys.exit(main())