Lessen dictionary size on same values for multiple keys?-CodePudding

Are there any datatype in python /collections module that would let me reduce my dictionary having same values (not into defaultdict though):

d = {'a': 'X', 'b': 'X', 'c': 'X', 'd': 'X', 'e': 'X', 'f': 'Z'}

to something smaller like

d = {('a','b','c','d','e'): 'X', ('f',): 'Z'}

So I can get same output 'X' when I pick

d['a'] == 'X'

I'm curious because 'X' is a long text in my code and It would be really easy to change all the values if mentioned only at one place.

CodePudding user response：

Try this!

d = {'a': 'X', 'b': 'X', 'c': 'X', 'd': 'X', 'e': 'X', 'f': 'Z'}
dct = {}
out = {}
for k in d.keys():
    if dct.get(d[k], None):
        dct[d[k]].append(k)
    else:
        dct[d[k]] = list(k)
for k in dct.keys():
    out[tuple(dct[k])] = k
print(out)

CodePudding user response：

If X is so big that you don't want it duplicated, you might want to store it separately and use another identifier to reference it. For example, you could do something like:

alias = {1: 'X', 2: 'Z'}
d = {'a': 1, 'b': 1, 'c': 1, 'd': 1, 'e': 1, 'f': 2}

# Query
alias[d['a']] == 'X'