Python: Regular expression use re.search

Question

I am iterating over directory structure that has many csv files, I am only interest some of the the csv files that are in that directory:

    if os.path.exists(lang_dir):
        dirs = os.listdir(lang_dir)
        for filename in dirs:
            if re.search(r'-.+-template-users-data.csv$',filename):

but for some reason file name with zu-en-template-users-data.csv doesn't get recognize, I have a feeling that the letter u in the filename has something to do with. Just to double check above segment of code, I directly went to folder and tried it with python interpreter, and with python interpreter files did get recognized correctly.

>>> import re
>>> import os
>>> dirs = os.listdir("PATH_FOR_THE_DIR/Data/2013_03_06_20_34/zu")
>>> for item in dirs:
...     if re.search(r'-.+-template-users-data.csv$',item):
...             print item
... 
zu-ab-template-users-data.csv
zu-ace-template-users-data.csv
zu-af-template-users-data.csv
zu-ak-template-users-data.csv
zu-als-template-users-data.csv
...

As you can see all the files that starts with zu showed up.. This means that my regular expression code segment is correct? (to my understanding)

And here is my code:

def templateUserCountStats(root_dir_path, lang_code_file_path):
    #dictionary to hold the template count data structure
    template_count_dict = dict()
    # getting lang codes from csv file
    for lang in getLanguageCodes(lang_code_file_path):
        # root level key of the dictionary
        template_count_dict[lang] = dict()
        lang_dir = os.path.join(root_dir_path, lang)
        # get all the files as s list in lang dir
        if os.path.exists(lang_dir):
            dirs = os.listdir(lang_dir)
            for filename in dirs:
                if re.search(r'-.+-template-users-data.csv$',filename):
                    lang2 = filename.split("-")[1]
                    #path = os.path.join(lang_dir, filename)
                    path = os.path.expanduser(lang_dir + '/' + filename)
                    #with open(path, 'rb') as template_user_data_file:
                    try:
                        template_user_data_file = open(path, 'r')
                        try:
                            csv_file_reader = csv.reader(template_user_data_file)
                            csv_file_reader.next()
                            # initializing user count for each language
                            template_count_dict[lang][lang2] = dict()
                            template_count_dict[lang][lang2]['level1'] = 0
                            template_count_dict[lang][lang2]['level2'] = 0
                            template_count_dict[lang][lang2]['level3'] = 0
                            template_count_dict[lang][lang2]['level4'] = 0
                            template_count_dict[lang][lang2]['level5'] = 0
                            template_count_dict[lang][lang2]['levelN'] = 0
                            #print filename
                            for row in csv_file_reader:
                                if row[0] == '1':
                                    template_count_dict[lang][lang2]['level1'] = template_count_dict[lang][lang2]['level1'] + 1
                                if row[0] == '2':
                                    template_count_dict[lang][lang2]['level2'] = template_count_dict[lang][lang2]['level2'] + 1
                                if row[0] == '3':
                                    template_count_dict[lang][lang2]['level3'] = template_count_dict[lang][lang2]['level3'] + 1
                                if row[0] == '4':
                                    template_count_dict[lang][lang2]['level4'] = template_count_dict[lang][lang2]['level4'] + 1
                                if row[0] == '5':
                                    template_count_dict[lang][lang2]['level5'] = template_count_dict[lang][lang2]['level5'] + 1
                                if row[0] == 'N':
                                    template_count_dict[lang][lang2]['levelN'] = template_count_dict[lang][lang2]['levelN'] + 1
                        except csv.Error, e:
                            print e
                    except Exception, e:
                        print e
                        logging.error(e)
            else:
                print "path doesn't exist"
    return template_count_dict

Answer 1

Is this because regular expression some how interpret u as a pattern...?

No this can't be the reason.

>>> bool(re.search(r'-.+-template-users-data.csv$', 'zu-en-template-users-data.csv'))
True

Your re pattern should work, the problem is somewhere else.