Functions for writing and reading dictionaries of lists to and from a CSV file.

dictlists.py

def write_dict_to_csv(dictionary, filename):
    """Write a dictionary of lists to a CSV file with the keys as the column
    heading. Will work with lists of unequal length."""
    with open(filename, 'w') as myfile:
        myfile.write(','.join(dictionary.keys())) # write header
        for line in itertools.izip_longest(*dictionary.values(), fillvalue=''):
            myfile.write('\n' + ','.join(line))
    print "Created file: " + os.getcwd() + '\\' + filename

def read_dict_from_csv(filename):
    """Read CSV file and read file into a dictionary of lists. First row becomes
    the keys to in the dictionary and each column of data is input as a list
    assigned to their respective key"""
    with open(filename, 'r') as myfile:
        lines = myfile.read().split('\n')
        keys = lines[0].split(',')
#    dictionary = {}
    dictionary = collections.OrderedDict()
    for key in keys:
        dictionary[key] = []
    for line in lines[1:]:
        if not line == '': # skip empty lines
            for i, item in enumerate(line.split(',')):
                if item:
                    dictionary.items()[i][1].append(item)
    return dictionary
           
def increment_filename(dictionary, filename):
    """Looks in current working directory, finds all filenames that match
    filename + digits + .csv, determines the highest number, increments by 
    1 and returns the new filename. Intended to be used with
    write_dict_to_csv()"""
    #get list of manifests, determine the highest number, add
    one and create new manifest file
    cwd = os.getcwd()
    expression = filename + r'\d+' + r'\.csv'
    file_matches = [item for item in os.listdir(cwd) if re.match(expression, item)]
#    mani_list = glob.glob(cwd + r'\manifest[0-9].csv')
    if file_matches:
        nums = []
        for f in file_matches:
            # Get digits in current file and join them
            nums.append(int(''.join([str(s) for s in os.path.split(f)[1] if s.isdigit()])))
        output_filename = filename + str((max(nums) + 1)) + '.csv'
    else:
        output_filename = filename + r'1.csv'
    return output_filename

def write_manifest(manifest):
    """Take dictionary called manifest from get_manifest() and write it to 
    a file. This is an example usage of increment_filename() and
    write_dict_to_csv()"""
    filename = increment_filename(manifest, 'manifest')
    write_dict_to_csv(manifest, filename)
    return filename

# Example usage
manifest = {'Name':['Bob', 'Sarah', 'Henry'], 'EyeColor':['Brown', 'Blue', 'Brown']}
write_manifest(manifest)