fp_exercise5.py

bands = [{'name': 'sunset rubdown', 'country': 'UK', 'active': False},
         {'name': 'women', 'country': 'Germany', 'active': False},
         {'name': 'a silver mt. zion', 'country': 'Spain', 'active': True}]
 
def assoc(_d, key, value):
    from copy import deepcopy
    d = deepcopy(_d)
    d[key] = value
    return d
 
def call(fn, key):
    def apply_fn(record):            
        return assoc(record, key, fn(record.get(key)))
    return apply_fn
 
def pipeline_each(data, fns):
    return reduce(lambda a, fn: map(fn, a),
                  fns,
                  data)
 
print pipeline_each(bands, [call(lambda x: 'Canada', 'country'),
                            call(lambda x: x.replace('.', ''), 'name'),
                            call(str.title, 'name'),
                            pluck(['name', 'country'])])
                            
# Implement pluck so that the pipeline_each call
# above returns the bands below.
 
# => [{'name': 'Sunset Rubdown', 'country': 'Canada'},
#     {'name': 'Women', 'country': 'Canada' },
#     {'name': 'A Silver Mt Zion', 'country': 'Canada'}]