Building and accessing an array of dictionaries

[Sam]

I would like to build an array of dictionaries. Most of the dictionary example on the net are for single dictionary.

dict = {'a':'a','b':'b','c':'c'}
dict2 = {'a':'a','b':'b','c':'c'}
dict3 = {'a':'a','b':'b','c':'c'}

arr = (dict,dict2,dict3)

What is the syntax to access the value of dict3->'a'?

Thank you.

 

[Chris Angelico]

I would like to build an array of dictionaries. Most of the dictionary example on the net are for single dictionary.

dict = {'a':'a','b':'b','c':'c'}
dict2 = {'a':'a','b':'b','c':'c'}
dict3 = {'a':'a','b':'b','c':'c'}

arr = (dict,dict2,dict3)

What is the syntax to access the value of dict3->'a'?

Technically, that's a tuple of dictionaries, and you may want to use a
list instead:

lst = [dict, dict2, dict3]

Like any other list or tuple, you can reference them by their indices:

lst[2] is dict3

lst[2]['a'] is dict3['a']

Hope that helps!

ChrisA

 

[Jussi Piitulainen]

I would like to build an array of dictionaries. Most of the
dictionary example on the net are for single dictionary.

dict = {'a':'a','b':'b','c':'c'}
dict2 = {'a':'a','b':'b','c':'c'}
dict3 = {'a':'a','b':'b','c':'c'}

arr = (dict,dict2,dict3)

What is the syntax to access the value of dict3->'a'?

This isn't a special case.

arr[2] to get the dictionary
arr[2]['a'] to get the value in the dictionary

'a' in arr[2] to find if there is such a key

arr[2].get('a') to get the value or None if the key isn't there
arr[2].get('a', 'd') to get a value even if the key isn't there

help(dict.get)

for key in arr[2]:
# to iterate over the keys

The exact same mechanisms are used no matter where you get the
dictionary from.

 

[Mark Lawrence]

Technically, that's a tuple of dictionaries

For the benefit of lurkers, newbies or whatever it's the commas that
make the tuple, not the brackets.

 

[Grant Edwards]

For the benefit of lurkers, newbies or whatever it's the commas that
make the tuple, not the brackets.

In _that_ example, yes. There are other cases where it's the
brackets (sort of):

foo('a','b','c') # three separate string objects are passed

foo(('a','b','c')) # a single tuple object is passed