generator and decorator examples

gistfile1.py

def by_token(fileobj):
    for line in fileobj:
        for token in line.split():
            yield token

import os

def open_file(func):
    def newfunc(filename):
        if os.path.exists(filename):
            return func(open(filename))
        else:
            return func(open(raw_input('type another file')))
    return newfunc

def hello(func):
    print 'applying a decorator'
    return func

@hello
@open_file
def dictreader(f):
    lines = f.read().split('\n')
    header = lines[0]
    keys = header.split(',')
    return [{k: v for k, v in zip(keys, line.split(','))}
            for line in lines[1:] if line.strip()]

dictreader = open_file(dictreader)

@open_file
def text(f):
    return f.read()

if __name__ == '__main__':
    import pprint
    pprint.pprint(dictreader('test.csv'))
    pprint.pprint(text('test.csv'))