python - Dictionary and List -

while reading through file convert given data in format of key , value. (value age of person)

for example if file has data:

20120101,56years 20120102,45years 20120103,67years 20120104,38years

.. , on until 20120131,21years.

i create dictionary , make date key ( in case let's line 1, key 20120101 ) , make value 56years.

when print out, separate dictionary every date. example:

{'20120101': ['56years']} {'20120102': ['45years']} {'20120103': ['67years']} {'20120104': ['38years']}

since see every dictionary has same starting values 201201, how can make single dictionary has 1 key 201201 , values appended in list?

example:

{'201201': ['56years', '45years', '67years', '38years'...]}

you can use collections.defaultdict

from collections import defaultdict d = defaultdict(list)

now, when key k , value v

d[k].append(v)

after adding first key,value pair, dictionary might like:

{'201201' : [56years]}

after reading key,value pair key "201201" , adding value d, dictionary like:

{'201201' : [56years,45years]}

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